I. noun a surprise attack by people lying in wait in a concealed position • seven members of a patrol were killed in an ambush
• [ mass noun]
there might be terrorists waiting in ambush.
II. verb — [with obj.] 1. make a surprise attack on (someone) from a concealed position • they were ambushed and taken prisoner by the enemy.
2. confront (someone) suddenly and unexpectedly with unwelcome questions • Tory representatives were ambushed by camera crews.
– origin 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.