concave
/kɒnˈkeɪv/ (bre, ipa) · /kɑːnˈkeɪv/ (ame, ipa) · /kän-ˈkāv ˈkän-ˌkāv/ (ame, mw)
concave — adjective
- concavepositive
- more concavecomparative
- most concavesuperlative
1. describing a surface that curves inward instead of being flat or sticking out —
describing a surface that curves inward instead of being flat or sticking out — like the hollow inner part of a bowl, spoon, or lens
Kofi held the concave grinding stone steady while his grandmother poured maize onto it.
describes the inward curve of a physical object
The mirror's concave surface made the reflection of each object look larger than it really was.
Yara noticed the concave curve where the old roof tiles overlapped one another like fish scales.
Pedro touched the concave scar on the tree trunk where lightning had struck years before.
A concave lens spreads light rays outward and is often used in glasses for nearsighted people.
- hollow
describes an empty space inside something; concave is more specific to the inward-curving surface itself
- recessed
describes something set back from a surface; concave focuses on the curve rather than the position
- sunken
suggests something has fallen or been pushed below a surface level; less precise for a smooth inward curve
- convex
curving outward rather than inward
用法筆記
The opposite of concave is convex (curving outward). Both terms are commonly used in geometry, optics, and descriptions of physical shapes.
常見錯誤
concave — noun
1. a surface, line, or hollow space that curves inward rather than being flat or st
a surface, line, or hollow space that curves inward rather than being flat or sticking out
The architect drew a gentle concave to show where the wall would curve inward.
concave used as a countable noun meaning an inward curve
Sakura traced the concave of the seashell with her fingertip, following its smooth spiral inward.
The shallow concave of the bay created a natural harbour protected from the open sea.
Neha pressed her thumb into the clay to form a small concave that would hold the candle.
- hollow
a more general word for an empty space; concave is more specific to a curved inward shape
- depression
describes a sunken area on a surface, often less regular than a concave curve
- indentation
suggests a mark or notch made by pressure; concave is smoother and more regular
- convex
an outward-curving surface or line
- protrusion
something that sticks out rather than curving in
用法筆記
The noun form is less frequent than the adjective. It is mainly used in technical writing, descriptive passages, or contexts where a specific inward-curving shape is named.