English Reference

Word

open

US/ˈoʊpən/

UK/ˈəʊpən/

Definitions

01not closed

A1 · Beginner

adj. not closed or blocked, allowing people or things to go through.

adj. physically unobstructed or uncovered; allowing passage or access.

“Please leave the door open so the cat can come inside.”

“The heavy gates remained open throughout the day to facilitate the delivery of construction materials to the site.”

Synonyms

unlockedunfastenedajar

Antonyms

02ready for business

A1 · Beginner Business

adj. ready for customers to enter or for work to happen.

adj. available for business, use, or public access during specified hours.

“Is the pharmacy still open at this time of night?”

“The museum is open to the public daily, though certain galleries may be restricted during private events.”

Antonyms

03honest and clear

B1 · Intermediate

adj. honest and willing to talk about your thoughts or feelings.

adj. transparent and candid in communication; not secretive or hidden.

“They have a very open relationship and talk about everything.”

“The manager encouraged an open dialogue during the meeting, insisting that every team member share their concerns without fear of reprisal.”

04not yet decided

B2 · Upper Intermediate

adj. not yet finished or decided.

adj. unresolved or not yet finalised; subject to further discussion or change.

“The date for the wedding is still open because we haven't found a place.”

“Whether the policy will be implemented this year remains an open question, as the budget has not yet been approved.”

Antonyms

05to unfasten or move

A1 · Beginner

v. to move something like a door or a lid so that it is no longer closed.

v. to move a door, lid, or similar barrier from a closed position to allow access.

“He opened the window to let some fresh air into the room.”

“She carefully opened the ancient manuscript, mindful of the fragile parchment that had been sealed for centuries.”

Synonyms

unsealunlock

Antonyms

06to start an event

B1 · Intermediate

v. to begin a meeting, a show, or a new business.

v. to formally begin or inaugurate an event, session, or commercial enterprise.

“The mayor will open the new hospital on Monday morning.”

“The chairman opened the annual general meeting by thanking the shareholders for their continued support during the fiscal year.”

Synonyms

startlaunchinaugurate

Antonyms

07a sports tournament

B1 · Intermediate Countable noun Sports

n. a competition that anyone can enter, including both professionals and amateurs.

n. a sporting competition in which both professional and amateur players are eligible to compete.

“She is practicing hard for the tennis Open next month.”

“Winning the national Open was the highlight of his career, especially as he was still considered an amateur at the time.”

08public view

B2 · Upper Intermediate Uncountable noun

n. a place or situation where everyone can see what is happening.

n. a state of being public or visible; often used in the phrase 'in the open'.

“It is better to discuss these problems in the open rather than keeping secrets.”

“Once the scandal was out in the open, the company had no choice but to issue a formal apology to its customers.”

Antonyms

Etymology

Adjective from Middle English open, from Old English open (“open”), from Proto-West Germanic opan, from Proto-Germanic upanaz (“open”), from Proto-Indo-European *upo (“up from under, over”). Cognates * Scots apen (“open”) * Saterland Frisian eepen (“open”) * West Frisian iepen (“open”) * Cimbrian offe (“open”) * Dutch open (“open”) * German offen (“open”) * Vilamovian ufa, uffa (“open”) * Yiddish אָפֿן (ofn, “open”) * Danish åben (“open”) * Icelandic opinn (“open”) * Norwegian Bokmål åpen (“open”) * Norwegian Nynorsk open (“open”) * Swedish öppen (“open”) Compare also Latin supinus (“on one's back, supine”), Albanian hap (“to open”). Related to up. Verb from Middle English openen, from Old English openian (“to open”), from Proto-West Germanic opanōn, from Proto-Germanic upanōną (“to raise; lift; open”), from Proto-Germanic *upanaz (“open”, adjective). Cognate with Saterland Frisian eepenje (“to open”), West Frisian iepenje (“to open”), Dutch openen (“to open”), German öffnen (“to open”), Danish åbne (“to open”), Swedish öppna (“to open”), Norwegian Bokmål åpne (“to open”), Norwegian Nynorsk and Icelandic opna (“to open”). Related to English up. Noun from Middle English open (“an aperture or opening”), from the verb. In the sports sense, however, a shortening of “open competition”.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

ADJECTIVE

open(A1)

Idioms

Domains

BusinessComputingEducationElectronicsEngineeringLawLogicMathematicsMedicineMusicSports

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.A1 MoversIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.2.0–3.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 1.0–1.50–23TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.120–224
Frequency
Very common
Level
A1 · BeginnerOxford
Updated

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English Reference