Hammerhead \Ham"mer*head`\ (-h[e^]d`), n.
1. (Zool.) A shark of the genus {Sphyrna} or {Zyg[ae]na},
having the eyes set on projections from the sides of the
head, which gives it a hammer shape. The {Sphyrna
zyg[ae]na} is found in the North Atlantic. Called also
{hammer fish}, and {balance fish}.
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2. (Zool.) A fresh-water fish; the stone-roller.
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3. (Zool.) An African fruit bat ({Hypsignathus monstrosus});
-- so called from its large blunt nozzle.
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