missing
adj
1
(a) that cannot be found or that is not in its usual place; lost 找不到的; 不在原处的; 失去的
The book had two pages missing/two missing pages. 那本书缺两页.
The hammer is missing from my tool-box. 我的工具箱里少了一把锤子.
(b) not present 不在场的
He's always missing when there's work to be done. 一到干活儿的时候, 他就不见了.
2 that cannot be found; absent from home 失踪的; 不在家的
a police file on missing persons 警方为失踪者立的档案
The child had been missing for a week. 孩子下落不明已有一周了.
3 (of a soldier, etc) neither present after a battle nor known to have been killed （指士兵等）（战斗後）下落不明的
Two planes were reported (as) missing. 据报有两架飞机失踪.
4 (idm 习语) a/the ,missing `link
(a) thing needed to complete a series or solve a puzzle （为完成一系列事物或解决一难题）所缺的一环.
(b) type of animal thought to have existed between the apes and early man 设想在类人猿和早期人类之间的过渡动物.