English Reference

Word

synonymous

Phoneticssyn·ony·mous

US/səˈnɑnəməs/

UK/sɪnˈɒnɪməs/

Definitions

01having the same meaning

B2 · Upper Intermediate

adj. having the same or a very similar meaning as another word.

adj. having the same or nearly the same meaning as another word or phrase in the same language.

“In many contexts, the word 'fast' is synonymous with 'quick'.”

“Lexicographers often debate whether any two terms are truly synonymous or if subtle register differences always exist between them.”

Usage

Usually follows the pattern 'X is synonymous with Y'.

Pitfall

The word 'big' is synonymous to 'large'.

The word 'big' is synonymous with 'large'.

Use the preposition 'with' after synonymous, not 'to'.

Antonyms

antonymousopposite

02closely associated

B2 · Upper Intermediate

adj. so closely connected with something that the two things seem the same.

adj. closely associated with or suggestive of a particular quality, idea, or brand.

“For many people, the brand name has become synonymous with luxury.”

“The politician's name became synonymous with corruption following the scandal, making a return to public office nearly impossible.”

Usage

Often used to describe reputations or brand identities.

03genetics

C2 · Proficiency Science Technical

adj. describing a change in a gene that does not change the protein it makes.

adj. relating to a DNA substitution that does not result in a change to the amino acid sequence of the encoded protein.

“A synonymous mutation usually does not affect the health of the organism.”

“The researchers focused on synonymous substitutions to estimate the background mutation rate without the interference of natural selection.”

Synonyms

Antonyms

nonsynonymous

Real-World Examples

“But as research over the past few decades has made clear, gender and sex are not synonymous .”
The Conversation 25 Aug 2026
“The 30-year-old has 108 goals in 278 games for Villa after joining from Brentford for a then-record £28m and has been synonymous with Villa's rise of the past six years.”
BBC News 24 Aug 2026

Etymology

From Medieval Latin synōnymus, from Ancient Greek συνώνυμος (sunṓnumos). By surface analysis, synonym + -ous.

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

Word family

ADJECTIVE

synonymous(B2)

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.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL 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: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
Frequency
Frequent
Level
B2 · Upper Intermediate
Updated

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English Reference