(in prescriptions) every day.
Origin of q.d.
From the Latin word quāque diē
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
quaque die (every day)
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.