hydrocephalus

noun

hy·​dro·​ceph·​a·​lus ˌhī-drō-ˈse-fə-ləs 

variants or less commonly hydrocephaly

ˌhī-drō-ˈse-fə-lē 

: an abnormal increase in the amount of cerebrospinal fluid within the cranial cavity (as from obstructed flow, excess production, or defective absorption) that is accompanied by expansion of the cerebral ventricles and often increased intracranial pressure, skull enlargement, and cognitive decline

Examples of hydrocephalus in a Sentence

Recent Examples on the Web

Alexis' tribute post comes a few weeks after the family announced that Joel was diagnosed with a brain condition called normal pressure hydrocephalus (NPH), which is a condition where excess cerebrospinal fluid builds up in the brain ventricles. —Hannah Sacks, People.com, 16 June 2025

Joel, 76, canceled his upcoming concert dates Friday and shared he was diagnosed with normal pressure hydrocephalus, or NPH, a condition in which cerebrospinal fluid builds up inside the skull and presses on the brain. —Rebecca Cohen, NBC news, 26 May 2025

But what exactly is normal pressure hydrocephalus, or NPH? More details: Billy Joel diagnosed with brain disorder, cancels all upcoming concerts What is normal pressure hydrocephalus? —David Oliver, USA Today, 24 May 2025

Billy Joel has announced the cancellation of all his upcoming tour dates due to a diagnosis of normal pressure hydrocephalus (NPH), a neurological condition that affects hearing, vision and balance. —Gabe Whisnant, MSNBC Newsweek, 23 May 2025

Word History

Etymology

New Latin hydrocephalus, from Late Latin, hydrocephalic, adjective, from Greek hydrokephalos, from hydr- + kephalē head — more at cephalic

First Known Use

1670, in the meaning defined above

Kids Definition

hydrocephalus

noun

hy·​dro·​ceph·​a·​lus ˌhī-drō-ˈsef-ə-ləs 

variants also hydrocephaly

-ˈsef-ə-lē 

: an abnormal condition in which an increased amount of cerebrospinal fluid causes an increase in the size of the ventricles of the brain and the size of the skull and the wasting away of the brain

Medical Definition

hydrocephalus

noun

hy·​dro·​ceph·​a·​lus -ˈsef-ə-ləs, British also -ˈkef- 

plural hydrocephali -ˌlī 

: an abnormal increase in the amount of cerebrospinal fluid within the cranial cavity (as from obstructed flow, excess production, or defective absorption) that is accompanied by expansion of the cerebral ventricles and often increased intracranial pressure, skull enlargement, and cognitive decline