(in prescriptions) as much as is sufficient; enough.
Origin of q.s.1
From the Latin word quantum sufficit
Definition for q.s. (2 of 2)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Medical definitions for q.s.
quantum satis (as much as is enough)
quantum sufficiat (as much as shall suffice)
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.