- (of a door or other opening) slightly open（门或其他开口处）半开的, 微开的：
as adv. the home help had left the window ajar that morning家政服务员那天早上让窗子半开着
as predic. adj. the door to the sitting room was ajar.通往起居室的门虚掩着。
词源
late 17th cent.: from A-2 'on'+obsolete CHAR （Old English cerr） 'a turn， return'.