Green’s Dictionary of Slang

1. the testicles.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

2. trousers.

1909

Ware Passing Eng. of Vict. Era 243/2: Thingembobs [...] One of the idiotic names for trousers.

3. the female breasts.

1940

R.L. Bellem ‘Death’s Passport’ in Goodstone Pulps (1970) 116/2: Her thingumbobs jiggled like mounds of aspic in an earthquake.