Green’s Dictionary of Slang

nob n.1

[var. on knob n.]

1. [late 17C+] (orig. UK Und., also nobb) the head; thus constr. with a to mean each, a time.

2. [late 18C–19C] (UK Und.) a hat.

3. [early 19C] in fig. use, to mean first or front.

4. [early 19C] a blow on the head.

5. [mid-19C] (UK Und.) a young boy prisoner who bullies weaker ones.

6. [mid-19C] a sovereign.

7. [mid-19C+] the penis [var. of knob n. (1c)].

8. [mid-19C; 1920s–30s] (mainly Aus.) a go, an item.

9. [late 19C–1910s] (Aus., also knob) a double-headed penny, esp. as used in the game of two-up, produced by filing down standard coins and welding them together.

10. [1970s+] a socially inept person [fig. use of sense 7].

In compounds

nob thatch (n.)

[mid-19C] human hair.

nob-thatcher (n.) (also knob-thatcher)

[late 18C–mid-19C] a wig-maker; a hat-maker.

nob-work (n.)

[early 19C] (UK Und.) ingenuity.

In phrases

keep one’s nob squared (v.)

[1900s] to keep calm.

off one’s nob (adj.) [1950s+]

drunk.