Meaning of q.d.s. in English:

q.d.s.

adjective

  • ‘to be taken four times a day’; = "q.i.d. [adverb]".

Origin

1930s; earliest use found in The Lancet. From the initial letters of post-classical Latin quater in die sumendus to be taken four times a day from quater in die four times a day + classical Latin sūmendus, gerundive of sūmere to take.