Tit \Tit\, n.

1. A small horse. --Tusser.

2. A woman; -- used in contempt. --Burton.

3. A morsel; a bit. --Halliwell.

4. [OE.; cf. Icel. titter a tit or small bird. The word probably meant originally, something small, and is perhaps the same as teat. Cf. Titmouse, Tittle.]

(Zo["o]l.)
   (a) Any one of numerous species of small singing birds belonging to the families Parid[ae] and Leiotrichid[ae]; a titmouse.
   (b) The European meadow pipit; a titlark.

Ground tit. (Zo["o]l.) See Wren tit, under Wren.

Hill tit (Zo["o]l.), any one of numerous species of Asiatic singing birds belonging to Siva, Milna, and allied genera.

Tit babbler (Zo["o]l.), any one of several species of small East Indian and Asiatic timaline birds of the genus Trichastoma.

Tit for tat. [Probably for tip for tap. See Tip a slight blow.]

An equivalent; retaliation.

Tit thrush (Zo["o]l.), any one of numerous species of Asiatic and East Indian birds belonging to Suthora and allied genera. In some respects they are intermediate between the thrushes and titmice.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Titmouse \Tit"mouse`\, n.; pl. Titmice. [OE. titemose, titmase; tit small, or a small bird + AS. m[=a]se a kind of small bird; akin to D. mees a titmouse, G. meise, OHG. meisa, Icel. meisingr. The English form has been influenced by the unrelated word mouse. Cf. Tit a small bird.]

(Zo["o]l.) Any one of numerous species of small insectivorous singing birds belonging to Parus and allied genera; -- called also tit, and tomtit.

Note: The blue titmouse (Parus c[oe]ruleus), the marsh titmouse (P. palustris), the crested titmouse (P. cristatus), the great titmouse (P. major), and the long tailed titmouse ([AE]githalos caudatus), are the best-known European species. See Chickadee.

Source: Webster's Revised Unabridged Dictionary (1913)