Everyone wants outrageous and opulent new vocabulary words. Whether you’re playing games (like Scrabble or Words with Friends) or writing for oratory, it’s overwhelmingly obvious that O-words add extra oomph. Want to outshine your officemates? Opine with some octosyllabic words that start with the letter O. Although it’s the 15th letter of the English alphabet, O comes first in oodles of ordinary (and outlandish) words! If you’re looking to outdo yourself, the letter O offers many opportunities for originality.
We’ve created this list of words for you, organized by the number of letters in each word. Many of these words have more than one meaning. For simplicity, we’ve only listed one definition for each word. Keep in mind, this word list doesn’t contain every single English word that starts with O; however, it’s a useful introduction to this very special letter.
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opaqueness – Noun | The characteristic of being non-transparent
outlandish – Adjective | Bizarre
8-Letter Words
objector – Noun | A person who disagrees or disapproves of something
obliging – Adjective | Helpful
oblivion – Noun | The state of being forgotten
oxymoron – Noun | The combination of two contradictory words
7-Letter Words
obelisk – Noun | A monolithic pillar with a pyramid at the apex
obelize – Verb | To annotate with an obelus, used to mark a questionable passage in an ancient text
obloquy – Noun | Abusive language or statements
obsequy – Noun | A burial rite
octopus – Noun | A cephalopod mollusk with eight arms
6-Letter Words
obsess – Verb | To engage in repetitive, preoccupied thinking
obtuse – Adjective | Difficult to understand
oculus – Noun | A circular window
oddity – Noun | The state of being unusual
5-Letter Words
oakum – Noun | A combination of fiber and tar used for caulking seams and packing joints
obeah – Noun | A system of belief involving witchcraft, practiced in the British West Indies and the Guianas
objet – Noun | An unusual decorative object, meant to be exhibited
ochre – Adjective | Yellowish orange color (also spelled ocher)
ocker – Noun | An uncultivated Australian male (Australian English)
odium – Noun | The state of being hated as a result of a blameworthy action
offal – Noun | The internal organs of a butchered animal
ogham – Noun | A fifth and sixth century Celtic writing system (also spelled ogam)
okapi – Noun | An African ungulate mammal, closely related to the giraffe
oldie – Noun | A popular song of a previous era
ouzel – Noun | Diving birds of the family Cinclidae
4-Letter Words
oaky – Adjective | Having a pleasant flavor characteristic of wine that’s been aged in oak casks
oast – Noun | A kiln for drying hops, malt, or tobacco
obia – Noun | A monster of west African folklore
obit – Noun | A notice of someone’s death with a brief biography
oboe – Noun | A woodwind instrument with a double-reed mouthpiece
obol – Noun | A unit of currency in ancient Greece
odic – Adjective | Pertaining to lyric poems
odyl – Noun | A hypothetical force believed to be responsible for magnetism, light, and hypnotism (also spelled odyle)
ogee – Noun | A pointed arch with an S-shaped curve on both sides
ogle – Verb | To eye impertinently with amorous intent
ogre – Noun | A giant monster that feeds on human flesh in legends and fairy tales
oink – Noun | The squealing sound made by a pig
okra – Noun | A vegetable, Abelmoschus esculentus, with green pods used for soups and stews
olio – Noun | A hodgepodge
omer – Noun | An ancient Hebrew unit of dry measurement
onus – Noun | Burden
onyx – Noun | Chalcedony with parallel layers of alternating colors
oops – Interjection | An expression of apology or dismay
ooze – Verb | To flow slowly through a small opening
opah – Noun | A brightly-colored, bony, oceanic fish
opal – Noun | An amorphous form of silica, often used as a gem
oryx – Noun | An African and Arabian antelope with dark facial markings
orzo – Noun | Rice-shaped pasta
ouch – Interjection | An expression of pain
ouzo – Noun | An anise-flavored, Greek liquor
oxid – Noun | A binary compound of oxygen with another element (also spelled oxide)
oyez – Interjection | Hear ye, an announcement by public criers before a proclamation
3-Letter Words
oaf – Noun | A big, stupid person
oba – Noun | A ruler or chief in the Benin region of western Africa (also spelled obba)
oca – Noun | The edible tuber of a South American wood sorrel
ohm – Noun | A unit for measuring electrical resistance
oho – Interjection | Expression of mockery
oik – Noun | An oaf, someone of low class (British English)
ooh – Interjection | An expression of amazement
ope – Verb | A poetic form of the word open
orc – Noun | A killer whale, Orcinus orca
ort – Noun | A scrap of food
oud – Noun | A stringed instrument, similar to a lute, found in the Middle East and North Africa
ova – Female egg cells, the plural of ovum
oxo – Noun | A trademarked, cube-shaped beef flavoring
2-Letter Words
or – Conjunction | A function word that indicates an alternative
ow – Interjection | Expression of pain
ox – Noun | Domestic bovine
oy – Interjection | Expression of exasperation or dismay
By looking at this list, you may be able to identify some common prefixes. Words that start with “oxy” have something to do with oxygen. Words beginning with “octo” involve the number eight. Understanding these linguistic patterns can help you to intuit what a word means, even when you don’t have a dictionary handy.
Use words that start with the letter O to open doors. Whether you choose to oblige others or offer objections, your opinions won’t seem obtuse when you use the most opportune word for the occasion. As your vocabulary outpaces that of others, you may find yourself overcoming opponents who obsess over word finders, word jumbles, and crossword puzzles. From oy to omnidirectional, this word list will keep you occupied with overachieving. Study these words, and you’ll be ornamenting your oratory with O-words in no time.
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Kari Lisa Johnson
I’m an award-winning playwright with a penchant for wordplay. After earning a perfect score on the Writing SAT, I worked my way through Brown University by moonlighting as a Kaplan Test Prep tutor. I received a BA with honors in Literary Arts (Playwriting)—which gave me the opportunity to study under Pulitzer Prize-winner Paula Vogel. In my previous roles as new media producer with Rosetta Stone, director of marketing for global ventures with The Juilliard School, and vice president of digital strategy with Up & Coming Media, I helped develop the voice for international brands. From my home office in Maui, Hawaii, I currently work on freelance and ghostwriting projects.
