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

Billy Joel’s wife, Alexis Roderick Joel, thanked fans and supporters on Monday for the outpouring of support following the Piano Man’s diagnosis of normal pressure hydrocephalus, a brain disorder. —Joseph Wilkinson, New York Daily News, 26 May 2025

On Friday, Joel canceled all the concerts on his schedule after revealing a diagnosis of normal pressure hydrocephalus (NPH), a brain disorder where excess cerebrospinal fluid accumulates in the brain’s ventricles. —Daniel Kreps, Rolling Stone, 25 May 2025

On Saturday, Brinkley – who was married to Joel from 1985 to 1994 – took to social media to share her support and offer words of encouragement as Joel prepares to battle normal pressure hydrocephalus (NPH), a rare disorder which affects his vision, hearing and balance. —Christina Dugan Ramirez, FOXNews.com, 25 May 2025

Billy Joel has canceled all his concerts due to a recent diagnosis of normal pressure hydrocephalus, according to a post on his official Instagram. —David Oliver, USA Today, 24 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