Concave



GRE 蓝宝 Barron TOEFL

解释

GRE 红宝书

• adj. 凹的
• ［英］ adj. 凹的 ( hollow and curved like the inside of a bowl)
• ［记］ con＋cave ( 空, 洞) -> 全部是洞 -> 凹的;
• ［同］ [ant]: aconvex ( 凸出的)

Webster Collegiate

I. adjective

• Etymology: Middle English, from Latin concavus, from com- + cavus hollow — more at cave
• Date: 15th century
• 1. hollowed or rounded inward like the inside of a bowl
• 2. arched in ; curving in — used of the side of a curve or surface on which neighboring normals to the curve or surface converge and on which lies the chord joining two neighboring points of the curve or surface

II. noun

• Date: 1552
• a concave line or surface

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