(usu 通常作 the rack) (formerly) instrument of torture consisting of a frame with rollers to which a person's wrists and ankles were tied so that his joints were stretched when the rollers were turned （旧时）拉肢拷问台（一种刑具）: put sb on the rack 对某人施以拉肢之刑. 
(idm 习语) on the `rack in severe pain or mental distress （肉体或精神上）受极大折磨.> rack v
1 [Tn] torture (sb) on the rack 以拉肢之刑拷问或折磨（某人）.
2 [Tn esp passive 尤用於被动语态] (of disease, pain or mental distress) cause agony to (sb) （指疾病﹑ 疼痛﹑ 苦恼等）使（某人）极为痛苦: racked with pain, fever, etc 因疼痛﹑ 发烧等而痛苦 * A coughing fit racked her whole body. 她一阵咳嗽全身都十分难受. * a voice racked by sobs/weeping 抽抽搭搭[哭哭啼啼]的痛苦的声音 * racked by (feelings of) guilt, remorse, doubt, etc 深受内疚﹑ 悔恨﹑ 怀疑等之苦.
3 (idm 习语) rack one's `brain(s) try very hard to think of sth or recall sth 苦思某事; 努力回忆某事: We racked our brains for an answer. 我们为寻找答案而绞尽脑汁. * I've been racking my brains (trying) to remember his name. 我一直在回想他的名字.
# `rack-rent n [C, U] unfairly high rent 过高的租金.