noggin

1. (dated outside dialects) A small measure of spirits equivalent to a gill.Examples: "I don’t know whether any of you, gentlemen, ever partook of a real, substantial, hospitable Scotch breakfast, and then went to a slight lunch of a bushel of oysters, a dozen or so of bottled ale, and a noggin or two of whisky to close up with."

2. (slang) The head.Examples: "Or maybe he bumped his noggin when he fell down—after he got clipped on the legs."; "She bumped her noggin on the bulkhead above the doorway, smiled in apology for her presumed clumsiness."

3. (biochemistry) A signalling molecule involved in embryo development, producing large heads at high concentrations.