Webster's Revised Unabridged Dictionary · 1913

Hardhead

Hardhead (-hed`) , noun

1.
Clash or collision of heads in contest. — Dryden
2.
(a) (Zoology) The menhaden. See Menhaden.
(b)
(Zoology) Block's gurnard (Trigla gurnardus) of Europe.
(c)
(Zoology) A California salmon; the steelhead.
(d)
(Zoology) The gray whale.
(e)
(Zoology) A coarse American commercial sponge (Spongia dura). [Local, United States]