Words That Start With O: Your Scrabble Cheat Sheet

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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Here are some words that start with O [2-15 letter words]

15-Letter Words

omnidirectional – Adjective | Involving all directions

opinionatedness – Noun | The quality of holding stubbornly to one’s own ideas and opinions

osteopathically – Adverb | By way of a system of medical practice based on manipulation of bones or other parts of the body

overstimulation – Noun | The act of invigorating too much

14-Letter Words

obstructionism – Noun | The practice of delaying the business before a legislative body or a legal proceeding

omnicompetence – Noun | The ability to deal with all matters

outrageousness – Noun | The quality of being shocking

overwhelmingly – Adverb | In an overpowering manner

13-Letter Words

objectionable – Adjective | Unacceptable

oceanographer – Noun | Scientist who studies the currents, the sea floor, and the fish and animals that live in the sea.

outdistancing – Verb | Leaving behind, outpacing

oxyhemoglobin – Noun | The bright red combination of oxygen and hemoglobin, which delivers oxygen to body tissues

12-Letter Words

obsolescence – Noun | The process of becoming outdated

octosyllable – Noun | A word or line with eight syllables

orchestrated – Verb | Carefully arranged for maximum effect

overpopulate – Verb | To populate with more than the environment can bear

11-Letter Words

opalescence – Noun | Milky iridescence 

opportunity – Noun | A favorable set of circumstances

orthodontia – Noun | Dental appliances used for orthodontic treatment

oxygenating – Verb | Combining or supplying with oxygen

10-Letter Words

obsequious – Adjective | Exhibiting over-eager attentiveness

occupation – Noun | Vocation, principle business

opaqueness – Noun | The characteristic being non-transparent

outlandish – Adjective | Bizarre

9-Letter Words

obsequious – Adjective | Exhibiting over-eager attentiveness

occupation – Noun | Vocation, principle business

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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  1. https://word.tips/words-start-with/o/
  2. https://www.merriam-webster.com
  3. https://www.collinsdictionary.com/us/
  4. https://www.dictionary.com
  5. https://scrabble.merriam.com/words/start-with/o
  6. https://www.wordnik.com/words/oxid
  7. https://www.britannica.com/art/obia

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