clue clock
verb: to catch by surprise with a really hard punch or hit, which usually leaves the recipient of the same word (used in noun form) dazed, confused or reeling, or in extreme cases, down or out for the count. The past tense form of the verb is generally representative of a single strike or blow, which effectively and convincingly takes the recipient down and/or out.
She didn't consider herself much of a fighter, but she waited in the dark room, just behind the door, with a cast iron skillet in hand, scared but ready to clue clock her uninvited guest across his forehead, if he proved crazy enough to continue following her around in her own home!