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

Software jobs include engineers to improve Neuralink’s implant manufacturing line and testing software, along with a role on the hippocampus team, referring to the part of the brain that plays a key function in learning and memory. —Andrea Guzmán, Austin American Statesman, 27 Feb. 2026

While studies have since recognized the phenomenon in humans — in a part of the hippocampus called the dentate gyrus — evidence has been mixed and the process poorly understood. —Lindsey Leake, NBC news, 26 Feb. 2026

The hippocampus of SuperAgers also has three times fewer tau tangles, one of the hallmarks of Alzheimer’s disease. —Sandee Lamotte, CNN Money, 25 Feb. 2026

It is integrated into other brain regions, most notably those that lay down memories (the hippocampus) and interpret outcomes (the prefrontal cortex). —Literary Hub, 13 Feb. 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