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

Their brains were analyzed, including RNA sequencing of the cortex to uncover gene activity, and whole genome DNA methylation mapping of the hippocampus for epigenetic changes. —New Atlas, 16 Aug. 2025

The olfactory cortex is closely connected to the amygdala, a part of the brain that processes emotions, and to the hippocampus, a key region for memory. —Margaret Talbot, New Yorker, 10 July 2025

Episodic memories are primarily formed and stored in the hippocampus, located in the temporal lobe of the brain. —Jack Knudson, Discover Magazine, 28 Apr. 2025

Meanwhile, the posterior portion of the hippocampus that lit up is the same region associated with an adult’s episodic memory banks. —Andrew Paul, Popular Science, 21 Mar. 2025

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