HYDROCEPHALUS

[hy.dro.ceph.a.lus] also hy.dro.ceph.a.ly n [NL hydrocephalus, fr. LL, hydrocephalic, adj., fr. Gk hydrokephalos, fr. hydr- + kephale head--more at cephalic] (1670): an abnormal increase in the amount of cerebrospinal fluid within the cranial cavity that is accompanied by expansion of the cerebral ventricles, enlargement of the skull and esp. the forehead, and atrophy of the brain