rat
/ræt; ræt/ n
1 rodent that looks like, but is larger than, a mouse 大鼠. =>illus at App 1 见附录1插图, page iii.
2 (infml fig 口, 比喻)
(a) disloyal person, esp one who deserts a cause in times of difficulty 不忠的人; （尤指困难时）背弃事业的人
So you've changed sides, you dirty rat! 那麽, 你改变立场了, 你这可耻的叛徒!
(b) unpleasant or despicable man 讨厌的人; 卑鄙的人.
3 (idm 习语) like a drowned rat => drown. the rat race (infml derog 口, 贬) fiercely competitive struggle, esp to keep one's position in work or life 激烈的竞争（尤指为保住职位或地位）
opt out of (ie withdraw from) the rat race 决定退出这场竞争. smell a rat => smell2. rat, v (-tt-)
1 [I] (usu 通常作 go ratting) hunt rats 去捕鼠.
2 [I, Ipr] (infml 口)
(a) ~ (on sb/sth) break an agreement, a promise, etc; fail to do sth one has undertaken to do 违背协议、 诺言等; 未履行责任.
(b) ~ (on sb) reveal a secret; betray sb 泄露秘密; 背叛某人
She's ratted on us here comes the head teacher! 她把我们出卖了--瞧校长都来了!