hip·po·cam·pus (hĭp'ə-kām'pəs) n.
pl.hip·po·cam·pi (-pī') A ridge in the floor of each lateral ventricle of the brain that consists mainly of gray matter and has a central role in memory processes.
[Late Latin, a sea horse with a horse's forelegs and a dolphin's tail (from its shape in cross section), from Greek hippokampos : hippos, horse; see ekwo- in Indo-European roots + kampos, sea monster.] hip'po·cam'pal (-pəl) adj.