Logo
PricingFSCE Hub
Log inTry for free
Learning

Lessons

Structured lessons & exercises — free samples

Fun Lessons

Interactive & engaging lessons

Vocabulary

Build your word power

Creative Writing

Prompts, techniques & games

Comprehension

Passages, skills & mock papers

Flash Cards

Quick revision cards

Knowledge Nuggets

Bite-sized learning tips

11+ Syllabus Hub

Every topic & question type explained

11+ Subjects

Explore all subjects

Exams & Tests

Mock Exams

Full exam simulations

Practice Tests

Try sample questions

Homework Zone

Weekly plans, groups & auto-planner

Games

Learn through play

Resources

Grammar Schools

School guides & information

Find Schools Near You

Nearest grammar schools by postcode

11+ Key Dates

Registration, test & apply-by dates

11+ Pass Marks

Qualifying scores by county

Readiness Quiz

Is your child ready? 2-min check

11+ Prep Guide

Complete preparation guide

FSCE Hub

Complete FSCE syllabus, schools & practice

FSCE Exam Guide

Exam preparation guide

Blog

Articles & expert tips

Contact Us

Get in touch with us

Join WhatsApp

Join our community group

11 Plus Vocabulary Words Starting With O

19 words with meanings, synonyms, antonyms & example sentences

These are the 19 vocabulary words starting with O from our free 565-word 11 plus vocabulary list, from oath to ostentatious including 5 advanced words of the kind that separates top verbal reasoning scores. Each entry shows the meaning, synonyms, antonyms and an example sentence — the exact skills tested in GL and CEM verbal reasoning, comprehension and cloze questions. You can also download the full list as a free PDF or practise these words with our free vocabulary games.

oath

/əʊθ/noun
Intermediate

A solemn promise, often calling upon God or something sacred as witness; a sworn declaration

Doctors take an oath to do no harm to their patients.

Synonyms: vow, pledge, promise, word

Antonyms: betrayal, denial, breach

object

/ˈɒbdʒɪkt/ (noun), /əbˈdʒekt/ (verb)noun/verb
Intermediate

A material thing that can be seen and touched; to express disapproval or opposition to something

There was a strange object floating in the water.

Synonyms: thing, item, article, oppose

Antonyms: approve, agree, support

objection

/əbˈdʒekʃən/noun
Intermediate

An expression of disapproval or opposition; a reason for disagreeing with something

The lawyer shouted 'Objection!' when the question was asked.

Synonyms: protest, opposition, disagreement, complaint

Antonyms: approval, agreement, acceptance

oblige

/əˈblaɪdʒ/verb
Intermediate

To make someone legally or morally bound to do something; to do something as a favour or kindness

The contract obliges both parties to meet certain conditions.

Synonyms: compel, require, accommodate, assist

Antonyms: release, free, refuse

obscure

/əbˈskjʊə/adjective/verb
Advanced

Not clearly expressed or easily understood; not well-known; to make unclear or difficult to see

The meaning of the ancient text remains obscure to scholars.

Synonyms: unclear, vague, unknown, hidden

Antonyms: clear, obvious, famous

obstinate

/ˈɒbstɪnət/adjective
Advanced

Stubbornly refusing to change one's opinion or course of action despite good reasons to do so

The obstinate child refused to eat his vegetables no matter what.

Synonyms: stubborn, headstrong, wilful, unyielding

Antonyms: flexible, cooperative, compliant

occupy

/ˈɒkjʊpaɪ/verb
Intermediate

To fill or take up a space, time, or position; to live or be situated in a place; to keep oneself busy

The new sofa will occupy most of the living room.

Synonyms: fill, inhabit, reside, engage

Antonyms: vacate, empty, leave

occur

/əˈkɜː/verb
Intermediate

To happen or take place; to exist or be found; to come into the mind suddenly

Earthquakes frequently occur in this region.

Synonyms: happen, take place, arise, develop

Antonyms: cease, stop, prevent

odour

/ˈəʊdə/noun
Intermediate

A distinctive smell, especially an unpleasant one; a scent or fragrance

A strange odour was coming from the basement.

Synonyms: smell, scent, aroma, fragrance

Antonyms: odourless, scentless

offend

/əˈfend/verb
Intermediate

To cause someone to feel hurt, upset, or angry; to commit an illegal act

I'm sorry if my comments offended you in any way.

Synonyms: upset, insult, hurt, displease

Antonyms: please, delight, compliment

omen

/ˈəʊmən/noun
Intermediate

A sign or warning of something that will happen in the future, especially something significant or bad

The black cat crossing their path was seen as a bad omen.

Synonyms: sign, portent, warning, indication

opportunity

/ˌɒpəˈtjuːnɪti/noun
Intermediate

A favourable time, situation, or set of circumstances that makes it possible to do something

The job interview is a great opportunity to showcase your skills.

Synonyms: chance, occasion, opening, prospect

Antonyms: obstacle, hindrance, barrier

oppose

/əˈpəʊz/verb
Intermediate

To actively resist or disagree with something; to compete against someone

Many citizens oppose the new tax increase.

Synonyms: resist, fight, challenge, contest

Antonyms: support, agree, approve

oppress

/əˈpres/verb
Advanced

To keep someone in hardship and subjection by exercising cruel or unjust authority; to cause distress

The dictator oppressed the citizens for decades.

Synonyms: persecute, tyrannize, subjugate, suppress

Antonyms: liberate, free, emancipate

option

/ˈɒpʃən/noun
Intermediate

A thing that is or may be chosen; the freedom or right to choose between alternatives

You have several options to choose from on the menu.

Synonyms: choice, alternative, selection, possibility

Antonyms: necessity, requirement, obligation

ordeal

/ɔːˈdiːl/noun
Intermediate

A very unpleasant and prolonged experience; a severe trial or difficult test of character

The hostages described their three-week ordeal in captivity.

Synonyms: trial, hardship, suffering, tribulation

Antonyms: pleasure, breeze, delight

origin

/ˈɒrɪdʒɪn/noun
Intermediate

The point or place where something begins or is created; a person's social background or ancestry

Scientists are studying the origin of the universe.

Synonyms: source, beginning, root, genesis

Antonyms: end, conclusion, result

orthodontist

/ˌɔːθəˈdɒntɪst/noun
Advanced

A dental specialist who corrects irregularities of the teeth, especially using braces and other devices

The orthodontist recommended braces to straighten her teeth.

Synonyms: dental specialist, teeth straightener, braces specialist

ostentatious

/ˌɒstenˈteɪʃəs/adjective
Advanced

Characterized by pretentious or showy display; designed to impress or attract notice

His ostentatious display of wealth annoyed his neighbours.

Synonyms: showy, flashy, pretentious, flamboyant

Antonyms: modest, humble, understated

← Words starting with NWords starting with P

Turn these 19 words into marks

The interactive word list adds British audio pronunciation, memory tips and progress tracking for every word — and our 6 free vocabulary games turn revision into play.

Open the Interactive Word ListPlay Vocabulary Games

More 11+ vocabulary resources