The Collaborative International Dictionary of English v.0.48:
Hen \Hen\, n. [AS. henn, hen, h[ae]n; akin to D. hen, OHG.
henna, G. henne, Icel. h?na, Dan. h["o]na; the fem.
corresponding to AS. hana cock, D. haan, OHG. hano, G. hahn,
Icel. hani, Dan. & Sw. hane. Prob. akin to L. canere to sing,
and orig. meaning, a singer. Cf. Chanticleer.] (Zool.)
The female of the domestic fowl; also, the female of grouse,
pheasants, or any kind of birds; as, the heath hen; the gray
Note: Used adjectively or in combination to indicate the
female; as, hen canary, hen eagle, hen turkey, peahen.
Hen clam. (Zool.)
(a) A clam of the Mactra, and allied genera; the sea clam
or surf clam. See Surf clam.
(b) A California clam of the genus Pachydesma.
Hen driver. See Hen harrier (below).
Hen harrier (Zool.), a hawk (Circus cyaneus), found in
Europe and America; -- called also dove hawk, henharm,
henharrow, hen driver, and usually, in America, marsh
hawk. See Marsh hawk.
Hen hawk (Zool.), one of several species of large hawks
which capture hens; esp., the American red-tailed hawk
(Buteo borealis), the red-shouldered hawk (Buteo
lineatus), and the goshawk.