gobsmacked

gobsmacked [gob-smakt] Word Origin adjective Chiefly British Informal.

1. utterly astounded; astonished.

Origin of gobsmacked gob3 + smack2 + -ed2 British Dictionary definitions for gob-smacked gobsmacked adjective

1. British slang astounded; astonished

Word Origin for gobsmacked C20: from gob ³ + smack ² Word Origin and History for gob-smacked gobsmacked adj.

by 1990, U.K. slang, from gob “mouth” + past participle of smack.