Hydrokephalon

Part of speech: noun

Definitions

1. A medical condition in which excess cerebrospinal fluid builds up inside the skull, enlarging the brain's ventricles and raising pressure on brain tissue
2. An abnormal buildup of fluid within the cranium that causes the head to swell, especially in infants, and can damage the brain if untreated
3. A neurological disorder marked by a dangerous surplus of cerebrospinal fluid in the brain cavities, often present from birth or following injury

Etymology: Ancient Greek physicians named a swollen skull "hydrokephalos," from "hydor," water, and "kephalē," head. The name described a condition thought to be fluid collecting in the head, which was then understood as a form of dropsy. The Greek term passed into Late Latin as "hydrocephalus," and English medical writers likely adopted it in the 1600s, though I am not certain of the earliest recorded use. The standard English spelling ends in "-us," so "hydrokephalon" with "-on" is a nonstandard variant of the same word. Greek compounds built this way are common in medicine. "Hydrocele," a fluid swelling of the scrotum, follows the same pattern, with "kēlē," meaning swelling, in place of "kephalē."