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hor. som.

American

abbreviation

(in prescriptions) at bedtime.

Etymology

Origin of hor. som.

From Latin hōrā somnī “at the hour of sleep”

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.