Blackcap \Black"cap`\ (-k[a^]p`), n.

1. (Zo["o]l.)
   (a) A small European song bird (Sylvia atricapilla), with a black crown; the mock nightingale.
   (b) An American titmouse (Parus atricapillus); the chickadee.

Source: Webster's Revised Unabridged Dictionary (1913)