Hy`dro*ceph"a*lus (?), n. [NL., fr. Gr. hydrocephalus; "y`dwr water + head.] Med.
An accumulation of liquid within the cavity of the cranium, especially within the ventricles of the brain; dropsy of the brain. It is due usually to tubercular meningitis. When it occurs in infancy, it often enlarges the head enormously.
© Webster 1913.