Mid 16th century: probably of Scandinavian origin and related to Icelandic titlingur 'sparrow'; compare with titling² and titmouse. Earlier senses were 'small horse' and 'girl'; the current sense dates from the early 18th century.

• Few words in English have such snigger-inducing contrasts in meaning. In the name for small songbirds, tit is probably of Scandinavian origin and related to Icelandic titlingur ‘sparrow’. It first appeared in English in the Middle Ages in the longer equivalent titmouse, though mice had nothing to do with it—the second element was originally mose, which also meant ‘tit’. It changed to mouse in the 16th century, probably because of the bird's small size and quick movements. In Old English a tit was a teat or nipple—it is from the same root as teat (Middle English). In modern English it is a term for a woman's breast, a use that arose in the USA in the early 20th century. Since the 1970s British tits and bums and American tits and ass have suggested crudely sexual images of women. As a name for a foolish person, used since the 19th century, tit may be the same word, or it may have evolved from twit.

Old English tit 'teat, nipple', of Germanic origin; related to Dutch tit and German Zitze. The vulgar slang use was originally US and dates from the early 20th century.

Mid 16th century: variant of obsolete tip for tap.