concave
/kɒnˈkeɪv/ (bre, ipa) · /kɑːnˈkeɪv/ (ame, ipa) · /kän-ˈkāv ˈkän-ˌkāv/ (ame, mw)
concave — 形容詞
- concavepositive
- more concavecomparative
- most concavesuperlative
1. describing a surface that curves inward instead of being flat or sticking out —
凹面的
向內彎曲的表面
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.
Kofi 穩穩地拿著那塊凹面的磨石，讓祖母把玉米倒上去。
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.
鏡子的凹面讓每個物體的反射看起來都比實物大。
Yara noticed the concave curve where the old roof tiles overlapped one another like fish scales.
Yara 注意到舊屋瓦彼此交疊形成的凹面曲線，像魚鱗一樣。
Pedro touched the concave scar on the tree trunk where lightning had struck years before.
Pedro 摸了摸樹幹上多年前遭雷擊留下的凹面疤痕。
A concave lens spreads light rays outward and is often used in glasses for nearsighted people.
凹面鏡片會將光線向外發散，常用於近視眼鏡。
- 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 — 名詞
1. a surface, line, or hollow space that curves inward rather than being flat or st
凹面；凹線
向內彎曲的面或線
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.
建築師畫了一道平緩的凹線，標示牆壁向內彎曲的位置。
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.
Sakura 用指尖循著貝殼的凹面，沿著平滑的螺旋線向內撫摸。
The shallow concave of the bay created a natural harbour protected from the open sea.
海灣的淺凹面形成了一座天然港口，不受外海風浪侵襲。
Neha pressed her thumb into the clay to form a small concave that would hold the candle.
Neha 用拇指在陶土上按出一個小凹面，用來放置蠟燭。
- 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.