pia mater

noun

: the thin vascular membrane that invests the brain and spinal cord internal to the arachnoid and dura mater

Examples of pia mater 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.
Her doctors noted in their report that the worms typically stay in the pia mater of the brain, a delicate innermost layer of tissue that surrounds the brain and spinal cord. Ars Technica, 11 Mar. 2025

Word History

Etymology

Middle English, from Medieval Latin, from Latin, tender mother

First Known Use

14th century, in the meaning defined above

Time Traveler
The first known use of pia mater was in the 14th century

Browse Nearby Words

Cite this Entry

“Pia mater.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pia%20mater. Accessed 24 Mar. 2025.

Medical Definition

pia mater

noun
pia ma·​ter -ˈmāt-ər How to pronounce pia mater (audio)
: the delicate and highly vascular membrane of connective tissue investing the brain and spinal cord, lying internal to the arachnoid and dura mater, dipping down between the convolutions of the brain, and sending an ingrowth into the anterior fissure of the spinal cord

called also pia

More from Merriam-Webster on pia mater

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!