Word
concave
Phoneticscon·cave, stress on the first syllable
US/ˈkɑnkeɪv/
UK/kɒnkˈeɪv/
Science
Definition
adj. curving inward like the inside of a bowl or a spoon. It is the opposite of convex, which curves outward.
adj. curving or hollowing inward; having a surface that is lower in the middle than at the edges. Often used in optics to describe lenses that diverge light.
Examples
“The inside of a spoon has a concave shape.”
“The architect designed a concave wall to help focus the sound toward the center of the auditorium.”
“A concave lens causes parallel rays of light to spread out, making it an essential component in corrective eyewear for people with nearsightedness.”
Examples
simple
“The inside of a spoon has a concave shape.”
contextual
“The architect designed a concave wall to help focus the sound toward the center of the auditorium.”
complex
“A concave lens causes parallel rays of light to spread out, making it an essential component in corrective eyewear for people with nearsightedness.”
Usage
Typically used attributively before a noun or predicatively after a linking verb like 'is' or 'appears'.
Pitfall
a concave mirror curves outward
a concave mirror curves inward
Learners frequently confuse 'concave' with 'convex'; remember that 'cave' implies a hollow space going inward.
Real-World Examples
“Such a polygon is described as concave because it has an indentation.” Etymology
From Middle English concave, from Old French concave, from Latin concavus.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Domain
- 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
- Occasional
- Level
- B2 · Upper Intermediate
- Updated
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QR code
englishreference.com/q/concave