To lie supine is to lie face up. To lie prone is to lie face-down.
What is the difference between supine and prone?
Supine and prone are unique terms with opposite meanings. If we’re lying down with our face to the ground, it’s called the “prone” or “prostrate” position. But if our face is up and with our backs to the ground, it’s called a “supine” position.
Garner’s Modern English Usage provides a notable example from the Heaven’s Gate incident in 1997, where an officer mistakenly announced, “‘[The victims] were lying prone on their backs.’” Moments later, a well-intending reporter announced, “‘they were prostrate on their backs,” although neither term was actually correct (Garner 734).
According to Garner, “supine” was the word that either speaker needed, as their original statements meant that the victims were “face-down on their backs” (734). Furthermore, to be “prostrate” means that you’re not simply face-down, but that your limbs are stretched out.
What’s additionally confusing about prone, supine, and prostrate is that they have similar secondary definitions: to be vulnerable or submissive. But as similar as they are, they do not mean the same thing:
- If something is prone, it is susceptible or vulnerable to something.
- When something is supine, it’s in a weak or passive position.
- When something is submissive or lacking vitality in the face of adversity, then it is prostrate.
What does supine mean?
English speakers primarily use “supine” as an adjective to describe something lying “face up.” More specifically, the adjective describes:
- A body lying face up.
- A hand’s position with the palm upward.
- The position of something with its front or ventral surface upward.
- “There is a systematic review that reports higher incidences of safe and effective PCNL treatment when performed in the complete supine position.”
- “Regardless of lung volume, healthy supine subjects present fewer predictors for poor oxygenation.”
- “Two clinical trials are studying the effects of supine positioning on percutaneous nephrolithotomy and radiation therapy outcomes.”
- “The study reports how small bowel complications are not as persistent in the supine position as they are in the prone.”
- “Intensive care unit nurses are comparing the outcomes of ARDS patients in the supine position during mechanical ventilation.”
Alternatively, supine can describe someone who cannot act for themselves. According to the New Oxford English Dictionary, the term especially applies to anyone who cannot act due to “moral weakness” or “indolence” (aka laziness) (“Supine” 1747).
- “The increase in cases appears to be a result of local supine leadership.”
- “The future of education depends on the abolishment of supine benchmarks.”
- “Your defendant’s supine philosophies undermine their supposed innocence.”
Related terms include the adverb “supinely,” which describes a manner that ‘shows weakness and passivity.’ The noun “supineness” means ‘the state of being supine.’
 Recumbent, stretched out.
 Acquiescent, enervated, effete, feeble, nonresistant, obeisant, passive, resigned, spineless, submissive, surrendering, weak, yielding.
 Erect, prone, raised, upright, vertical.
 Contrary, defiant, disobedient, incompliant, indomitable, insubordinate.
What does supine mean in Latin grammar?
Outside its adjective form, “supine” is a noun that describes a type of suffix (so to speak) within Latin Grammar (1747). As explained by Allen and Greenough’s Latin Grammar, “The supine is a verbal abstract of the 4th declension, having no distinction of tense or person, and limited to two uses.”
The two “supines,” in this case, exist as the accusative case (-um) and ablative singular case (-ū):
- “The supine in -um occurs in “verbs of motion to express purpose.”
- The supine in -ū occurs within a few adjectives and nouns to “denote an action in reference to which the quality is asserted.”
Lexico provides an example with Latin “mirabile dictu,” meaning ‘wonderful to relate.’
Etymology of supine
Both word forms of supine entered the English language in the 15th century. The adjective supine stems from Middle English suppyne from Latin supinus, meaning ‘bent backward,’ or, figuratively speaking, ‘indolent’ and ‘inactive’ (1747). Regarding Latin grammar, the noun supine comes from Middle English supyn from Late Latin supinum verbum (‘supine verb’).
What does prone mean?
As an adjective, the word prone describes something as:
- Lying flat on a surface;
- Lying flat with the face or ventral surface facing down;
- With the forearm positioned so that the hand palm faces downward, or;
- (Archaic) With a downward slope or direction.
- “The Oncology Review is publishing the effects of prone positioning while treating prostate cancer via radiotherapy.”
- “According to The Lancet, there is a significant difference between the dorsal lithotomy and prone positions.”
- “Computed tomography documents cardiovascular changes of turning prone.”
- “The prone position is shown to increase pulmonary artery pressure, arterial occlusion pressures, and central venous pressures.”
- “She is writing a meta-analysis on the effects of prone positions for patients with acute respiratory distress syndrome.”
The adjective prone also appears in the expression “prone to” when it describes something that is ‘likely to do something,’ ‘be liable for,’ or ‘suffer from’ (especially when the “something” is unfortunate or unwelcome) (“Prone” 1398).
- “Full-time students with multiple jobs are prone to pulling all-nighters.”
- “My sensitive friend is prone to periods of depression.”
- “I’d be more prone to do something if the issue affected my family members.”
Related terms include the adverb “pronely,” which means ‘to lie in a prone manner’ or ‘in a frequent and likely manner.’ The noun “proneness” also describes ‘the state of being prone.’
 Flat, horizontal, recumbent, reposing.
 Apt, disposed, given, inclined, liable, open, predisposed, subject, susceptible, tending.
 Erect, raised, supine, upright, vertical.
 Averse, disinclined, indisposed, unwilling.
Is prone a verb?
According to Merriam-Webster’s Dictionary, prone is also a transitive verb that means:
- ‘To place oneself or another in a prone position,’ or;
- ‘To cause or order someone to lie flat with their face and stomach to the ground.’
Verb forms include “prone” (present tense), “proned” (past participle), and “proning” (present participle).
- “Nurses may prone patients to increase oxygenation.”
- “Patients are proned so that the machine can observe pulmonary movement in the anterior region.”
- “Elsevier Inc. published several resources on safe proning techniques.”
Etymology of prone
The adjective prone is a 14th-century term that originated from Latin pronus for ‘leaning forward’ (from pro ‘forward’). The use of “prone” as a verb arrived much later in 1971.
FAQ: How to use supine vs. prone in a sentence?
How to use supine and prone as verbs?
We already know that the word “prone” exists as a verb, but the same usage also applies to supine (well, kind of). The verb form of “supine” is “supinate,” which the Cambridge Dictionary defines as ‘to turn the bottom of a body part upwards’ or ‘to put yourself or another in a supine position.’
- “… we’re supinating, proning, supinating, proning, and it can go on for days.”
- “Proned patients must periodically be turned onto their backs again, called supinating because that position is better for some nursing tasks…”
- “Some of these patients will lose the benefits once we supinate them, and then we have to prone them again…”
- “People are saying go ahead and prone them…”
Should I write “supine on one’s back” or “lying on one’s back”?
Just like the phrases “new innovation” or “final outcome,” the expression “supine on one’s back” is redundant: “supine” already means ‘lying on one’s back.’ The same is true of “prone,” where it is best to avoid writing, “prone on one’s stomach.”
- “Now, of course, you can spend a whole workday supine, with your boss none the wiser.” — The Wall Street Journal
- “Seven patients, who started in the supine position, subsequently refused [the] prone position and received their whole treatment supine.” — Radiother Oncol.
- “… the supine position was similar to the prone position for percutaneous stone removal.” — European Urology
How to tell when supine is a position or an insult?
In most cases, you’ll find the adjective “supine” to describe someone who is lying flat with their back to the ground. For instance, a yoga teacher might instruct their students to rest in a “supine position” for their savasana. You could even use “supine” to describe a public existential crisis:
“Defeated by my inadequacy to use self check-out, I questioned my supine existence on the grocery store floor.”
Notice how “supine” appears to be a position and an insult? Well, that’s because it is. As an insult, the adjective describes someone who is morally indolent or inadequate. The example is admittedly metaphorical, but this is one way to use the adjective in a manner that is more difficult to confine.
When “supine” is explicitly slanderous, there will be no doubt as to whether it’s describing someone’s character. A famous example comes from British Prime Minister Boris Johnson, who accused members of the London Assembly of being “great supine protoplasmic invertebrate jellies.”
Equally interesting examples include:
- “Church control of education, enabled by supine politicians, was fundamental and near total.” — The Irish Time
- “For there is much that seems supine about some journalism at present.” — The Argus
Test how well you understand the difference between supine and prone with the following multiple-choice questions.
- True or false: the only people who use the words supine and prone are health care professionals.
- Someone who is lying face-down is in a ___________ position.
d. B or C
- Someone who is lying face-down and with their limbs spread out is in a ___________ position.
d. B or C
- If some is in a “supine” position, they are _____________.
a. Lying on their back with their face down
b. Lying on their stomach with their face upward
c. Lying on their back with their face upward
d. Lying on their stomach with their face down
- Which is not a verb form of “supine” or “prone”?
- Ayer, M., Ed. “The Supine.” Allen and Greenough’s Latin Grammar, Dickinson College Commentaries, n.d.
- Bayley, Andrew John et al. “A randomized trial of supine vs. prone positioning in patients undergoing escalated dose conformal radiotherapy for prostate cancer.” Radiotherapy and oncology: journal of the European Society for Therapeutic Radiology and Oncology vol. 70,1 (2004): 37-44, PubMed. doi:10.1016/j.radonc.2003.08.007.
- Belluck, P. “Low-Tech Way to Help Some Covid Patients: Flip Them Over.” The New York Times, NYTimes.com, 13 May 2020.
- “Boris Johnson Calls London Assembly ‘Great Supine Protoplasmic Invertebrate Jellies’ – LBC.” LBC, YouTube.com, 25 Feb 2013.
- Boylan, P. “State and church and healthcare.” The Irish Times, IrishTimes.com, 15 Jan 2021.
- De Sio, Marco et al. “Modified supine versus prone position in percutaneous nephrolithotomy for renal stones treatable with a single percutaneous access: a prospective randomized trial.” Eur Urol vol. 54,1 (2008): 196-202. doi:10.1016/j.eururo.2008.01.067.
- Garner, B. “Prone; prostrate; supine.” Garner’s Modern American Usage, 3rd ed., Oxford University Press, 2009, p. 734.
- Gilson, M. “Why journalists must always be a nuisance.” The Argus, TheArgus.co.uk, 29 Mar 2016.
- Harper, D. “Supine (adj.).” Online Etymology Dictionary, Etymonline.com, 2021.
- “Supinate.” Cambridge Dictionary, Cambridge University Press, 2021.
- “Supine.” Lexico, Oxford University Press, 2021.
- “Supine.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., 2021.
- “Supine.” The New Oxford American Dictionary, 3rd ed., Oxford University Press, 2010, p. 1747.
- “Supinely.” Cambridge Dictionary, Cambridge University Press, 2021.
- “Prone.” Lexico, Oxford University Press, 2021.
- “Prone.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., 2021.
- “Prone.” The New Oxford American Dictionary, 3rd ed., Oxford University Press, 2010, p. 1398. Wolfe, R. “How to Avoid the 5 Worst Bedroom Interior-Design Mistakes.” The Wall Street Journal, WSJ.com, 15 Jan 2021.