at-

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Word Origin and History for at-

assimilated form of ad- "to, toward, before" before stems beginning in -t-; see ad-.

Online Etymology Dictionary, © 2010 Douglas Harper

at- in Medicine

at-

pref.
  1. Variant ofad-
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.