The glans penis, the sensitive bulbous structure at the end of the penis also known as the head of the penis. (also spelled knob)
the head (somewhat archaic) Used in one version of the Nursery Rhyme: Jack and Jill went up the hill to fetch a pail of water; Jack fell down and broke his crown, and Jill came tumbling after. Up Jack got and home did trot, as fast as he could caper; to old Dame Dob to mend his nob, with vinegar and brown paper
If you refer to a group of people as the nobs, you mean they are rich or come from a much higher social class than you do. the nobs who live in the Big House. A person of wealth or social standing: "The nobs were forever snubbing the snobs" (Conor Cruise O'Brien). a rich person with a high social position
[ 'näb ] (noun.) circa 1700. * From "nobleman" or "member of the nobility" (Doubtful)
* From "white-nob" (Eighteenth century) or "white-head", referring to the powdered wigs used by those affecting upper middle-class status.