A person's head or brain, used informally or humorously; also a small cup or mug.
Of uncertain origin, possibly from Dutch 'nog' (peg or stopper), referring to a wooden mug or small drinking vessel, which then transferred to mean 'head' as slang.
This word bounced between meanings—originally a mug, then slang for head—showing how body-part slang often comes from objects we compare our bodies to.
Complete word intelligence in one call. Free tier — 50 lookups/day.