Meaning of q.d. in English:

q.d.

adjective

  • 1Q.i.d. adverb (now disused).

  • 2‘every day’.

Origin

Early 20th century; earliest use found in George Gould (1848–1922). From the initial letters of post-classical Latin quater in die four times a day or classical Latin quāque diē every day (from quāque, ablative feminine of quisque each (from quis, interrogative and indefinite pronoun + -que) + diē, ablative of diēs day).