hippocampus

noun

hip·​po·​cam·​pus ˌhi-pə-ˈkam-pəs How to pronounce hippocampus (audio)
: 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 adjective

Examples of hippocampus in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
To determine the source of engram-to-be cells, the researchers created a neural network model that simulated activity in the hippocampus. Jack Knudson, Discover Magazine, 28 Apr. 2025 At an average age of 70, participants underwent brain magnetic resonance imaging (MRI) scans to assess the structure and function of the hippocampus, a part of the brain crucial for forming new memories and one of the first brain regions affected by dementia. Tom Gavin, EverydayHealth.com, 24 Mar. 2025 One leading hypothesis suggests that the part of our brain responsible for memory – the hippocampus – is underdeveloped at that stage of life and isn’t ready to store memories. Michael Irving, New Atlas, 20 Mar. 2025 But there was a significant correlation between staring longer and activity in the hippocampus, suggesting that the kids were more likely to stare at something that had triggered the memory formation process during their first viewing. John Timmer, Ars Technica, 21 Mar. 2025 See All Example Sentences for hippocampus

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

Time Traveler
The first known use of hippocampus was in 1695

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Cite this Entry

“Hippocampus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hippocampus. Accessed 16 May. 2025.

Medical Definition

hippocampus

noun
hip·​po·​cam·​pus ˌhip-ə-ˈkam-pəs How to pronounce hippocampus (audio)
plural hippocampi -ˌpī How to pronounce hippocampus (audio) -(ˌ)pē How to pronounce hippocampus (audio)
: 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

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