1. [16C+] (also nod, noll) the head.
2. [late 16C+] used fig. to denote the head as a seat (or not) of intelligence.
3. [late 18C–mid-19C] an empty, foolish head; thus a fool.
[late 19C+] confused, forgetful.
[18C] a wig.
[1900s] (US) a fool.
[late 17C] a club.
[18C] a wig-maker.
[1950s+] to use one’s head, to act sensibly, to think things through (cf. use one’s noodle under noodle n.1 ).