- a surprise attack by people lying in wait in a concealed position埋伏; 伏击：
seven members of a patrol were killed in an ambush
巡逻队七名队员在伏击中被击毙
mass noun there might be terrorists waiting in ambush.可能有恐怖分子埋伏。
with obj.(常作be ambushed)
1- make a surprise attack on (someone) from a concealed position进行伏击：
they were ambushed and taken prisoner by the enemy
他们受到伏击, 成了敌人俘虏。
1.1
- confront (someone) suddenly and unexpectedly with unwelcome questions突然向（某人）提出尴尬的问题：
Tory representatives were ambushed by camera crews.
保守党代表突然遭到摄影记者的质难。
词源
Middle English （in the sense 'place troops in hiding in order to surprise an enemy'）： from Old French embusche (noun)， embuschier (verb)， based on a late Latin word meaning 'to place in a wood'; related to BUSH1.