18 cat out of the bag

cat out of the bag
reveal a secret carelessly or by mistake (无意中)泄露秘密; 露马脚
    I wanted mother´s present to be a secret, but my sister let the cat out of the bag. 给母亲的礼物我原想保密, 可是妹妹却露了马脚. like a ,cat on hot `bricks (infml 口) very nervous 非常紧张; 像热锅上的蚂蚁; 如坐针毡
    He was like a cat on hot bricks before his driving test. 他面临驾驶考试, 紧张得像热锅上的蚂蚁. no room to swing a cat => room. play cat and mouse/play a cat-and-mouse game with sb (infml 口) keep sb in a state of uncertain expectation, treating him alternately cruelly and kindly 对某人时好时坏、 忽冷忽热. put/set the `cat among the pigeons (infml 口) introduce sb/sth that is likely to cause trouble or disturbance 引来可能招惹是非或麻烦的人或事物
    The new vicar´s a Marxist that´ll set the cat among the pigeons! 新来的牧师是马克思主义者--这下子可要鸡犬不宁了. rain cats and `dogs => rain2. wait for the cat to jump/to see which way the cat jumps => wait1.
cat n (US infml 口) = caterpillar tractor (caterpillar).
CAT abbr 缩写 = (Brit) College of Advanced Technology工学院.