titmouse

[tit-mous] /ˈtɪtˌmaʊs/
noun, plural titmice
[tit-mahys] /ˈtɪtˌmaɪs/ (Show IPA)
1.
any of numerous, widely distributed, small songbirds of the family Paridae, especially of the genus Parus, having soft, thick plumage and a short, stout, conical bill.
Compare tufted titmouse.
Origin
1275-1325; Middle English tit(e)mose (see tit1); mose, Old English māse titmouse; cognate with German Meise titmouse, Old Norse meis- in meisingr kind of bird; modern mouse by folk etymology
British Dictionary definitions for titmouse

titmouse

/ˈtɪtˌmaʊs/
noun (pl) -mice
1.
(usually pl) any small active songbird of the family Paridae, esp those of the genus Parus See tit1
Word Origin
C14 titemous, from tite (see tit1) + mouse
Word Origin and History for titmouse
n.

"small, active bird," early 14c., titmose, from tit (n.2), expressing something small, + Old English mase "titmouse," from Proto-Germanic *maison (cf. Dutch mees, German meise), from adj. *maisa- "little, tiny." Spelling influenced 16c. by unrelated mouse.