Asks for permission to enter a room.

(historical) A can (often with a spout and handle) filled with hot water, used to warm a room, to keep one's feet warm, or to supply water for such things as shaving, washing, etc.

Used sarcastically to draw attention to a motive or agenda.

Synonym of look who's talking

(US) A cooked dish made by standing a prepared chicken upright on a partially filled can of beer and cooking it slowly in a barbecue or oven, so that the beer evaporates and permeates the meat.

A pseudo-telephone constructed from two tin cans (or paper cups, etc.) attached at the ends with string.

(colloquial, rhetorical question) A rhetorical question in response to a question whose answer is an emphatic yes.

plural of tin can telephone

(idiomatic) Alternative form of pigs might fly

A person, place, thing, or situation can be very different from how it seems or appears to be at first glance.