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

Last month, Joel announced the cancellation of his forthcoming performances due to his recent diagnosis of normal pressure hydrocephalus – a condition that occurs when cerebrospinal fluid builds up inside the skull, pressing on the brain. —Tyler Jenke, Billboard, 5 June 2025

Joel last month postponed all tour dates disclosing a diagnosis of normal pressure hydrocephalus (NPH), stemming from an onstage fall during a concert last February in Connecticut. —Jill Goldsmith, Deadline, 4 June 2025

Because normal pressure hydrocephalus typically develops gradually and can mimic symptoms of other neurodegenerative diseases, such as Alzheimer’s or Parkinson’s disease, it is often misdiagnosed. —Danielle Wilhour, The Conversation, 28 May 2025

According to the Cleveland Clinic, normal pressure hydrocephalus occurs when fluid buildup inside or around the brain disrupts brain function. —Brendan Morrow, USA Today, 27 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