What is the meaning of Hammerhead?

The portion of a hammer containing the metal striking face (also including the claw or peen if so equipped).

Any of various sharks of the genera Sphyrna or Zygaena having the eyes set on projections from the sides of the head, which gives it a hammer shape.

A fresh-water fish; the hogsucker, Hypentelium nigricans, in the sucker family Catostomidae.

An African fruit bat, the hammer-headed fruit bat, Hypsignathus monstrosus, so called from its large blunt nozzle.

Scopus umbretta (hammerkop).

A stupid person, a dunce.

A turn-around; a parking area constructed in a subdivision for initial access and construction.

A kind of ribozyme; hammerhead ribozyme.

Source: wiktionary.org