: small grains of calcareous matter in the brain (as in the pineal gland) that occur especially in association with aging
called also acervulus, acervulus cerebri
Cite this Entry
“Brain sand.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/brain%20sand. Accessed 31 Oct. 2025.
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