Green’s Dictionary of Slang

tit n.1

[despite SE teat/tit n.2 (1), ety. is onomat. term meaning anything small + Scand. dial. terms titta, a little girl, tita, a small fish etc.]

1. with ref. to horses.

(a) [mid-16C–1910s] a small or half-grown horse [SE until c.1800].

(b) [19C] a coach horse.

2. [late 16C+] a girl or woman, esp. in derog. or generic use, e.g. a tasty bit of tit, but also as a term of affection, often as little tit.

3. [18C+] generic for a person of either sex.

4. [early 18C–1900s] the vagina.

In compounds

tit-bit (n.) [mid-17C–early 19C]

1. the vagina.

2. the penis.

3. (also tid-bit) a young woman.

4. (US) an ineffectual person.

5. (US , also tid-bit) the female breast.

tit-man (n.)

[mid-19C] a carter.

In phrases

jackel-tit (n.)

[mid-19C] (UK Und.) a stolen horse.

jolly tit (n.)

[early 18C] a pleasant companion.

willing tit (n.) [note B.E.: ‘Willing-Tit, a little horse that Travels chearfully’]

[18C–early 19C] a complaisant woman.