q.d. [L, quaque, every, die, day] , 1. (Obsolete) an abbreviation formerly used to indicate “every day.” Because of the danger of misinterpretation, q.d. is on The Joint Commission’s “Official ‘Do Not Use’ List of Abbreviations.” It is also identified on the Institute for Safe Medication’s “List of Error-Prone Abbreviations, Symbols, and Dose Designations.” Now written out as daily.2. abbreviation for quartile deviation.
