hippocampus

noun

hip·​po·​cam·​pus ˌhi-pə-ˈkam-pəs 

plural hippocampi ˌhi-pə-ˈkam-ˌpī  -(ˌ)pē 

: a curved elongated ridge that extends over the floor of the descending horn of each lateral ventricle of the brain, that consists of gray matter covered on the ventricular surface with white matter, and that is involved in forming, storing, and processing memory

hippocampal

ˌhi-pə-ˈkam-pəl 

adjective

Examples of hippocampus in a Sentence

Recent Examples on the Web

This type of learning in the hippocampus, the brain’s memory hub, is caused by an electrical change that affects multiple neurons at once and unfolds across several seconds. —Yasemin Saplakoglu, Quanta Magazine, 24 Apr. 2026

Exercise also increases levels of BDNF, a growth factor that helps maintain the hippocampus, the part of the brain responsible for forming new and long-term memories, and one that often shrinks in dementia, said Ashwini Nadkarni, assistant professor of psychiatry at Harvard Medical School. —The Washington Post, San Diego Union-Tribune, 21 Apr. 2026

The hippocampus is central to this process, building what neuroscientists sometimes call cognitive maps—internal models of space constructed from actual navigation and sensory experience. —Tim Requarth, Longreads, 9 Apr. 2026

That molecule boosts cognitive function, generates new neurons and improves connections between neurons, especially in the hippocampus, the part of the brain that converts short-term memory to long-term memory, Wanigatunga said. —Kaitlin Sullivan, NBC news, 8 Apr. 2026

Word History

Etymology

New Latin, from Greek hippokampos seahorse, from hippos horse + kampos sea monster — more at equine

First Known Use

1695, in the meaning defined above

Rhymes for hippocampus

• campus
• grampus

Medical Definition

hippocampus

noun

hip·​po·​cam·​pus ˌhip-ə-ˈkam-pəs 

plural hippocampi -ˌpī  -(ˌ)pē 

: a curved elongated ridge that is an important part of the limbic system, extends over the floor of the descending horn of each lateral ventricle of the brain, consists of gray matter covered on the ventricular surface with white matter, and is involved in forming, storing, and processing memory see pes hippocampi