Source : Webster's Revised Unabridged Dictionary (1913)

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}.] (Zo["o]l.)
   The female of the domestic fowl; also, the female of grouse,
   pheasants, or any kind of birds; as, the heath hen; the gray
   hen.

   Note: Used adjectively or in combination to indicate the
         female; as, hen canary, hen eagle, hen turkey, peahen.

   {Hen clam}. (Zo["o]l.)
   (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} (Zo["o]l.), 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} (Zo["o]l.), one of several species of large hawks
      which capture hens; esp., the American red-tailed hawk
      ({Buteo borealis}), the red-shouldered hawk ({B.
      lineatus}), and the goshawk.

Source : WordNet®

hen
     n 1: adult female chicken [syn: {biddy}]
     2: adult female bird
     3: flesh of an older chicken suitable for stewing
     4: female of certain aquatic animals e.g. octopus or lobster