pin /pin/I. n. ［c］1. 别针，大头针：a safety pin 安全别针；take out a pin 拔出一根针；be on pins and needles如坐针毡 2.针饰，徽章，像章，纪念章：a tie-pin 领带别针；a hat-pin 帽子饰针 3.销子，钉子，闩：pin bent 弯曲销 ‖II. vt. (pinned; pinning) 1. 别住，钉柱： pin papers together 把文件(用大头针)别在一起；pin up a notice 钉上一张告示；pin up one’s hair 用发夹把头发夹住 2. 用于短语动词pin down了解详情：She refuses to be pinned down on how much her business lost last year. 她拒绝告知她企业去年的亏损情况。Investigators are trying to pin down the cause of yesterday’s fire. 调查人员竭力想查清昨天火灾的起因。