Dose
late Middle English: from French, via late Latin from Greek dosis ‘gift’, from didonai ‘give’.
wiktionary
Borrowed from Middle French dose, from Late Latin dosis, from Ancient Greek δόσις(dósis, “a portion prescribed”, literally “a giving”), used by Galen and other Greek physicians to mean an amount of medicine, from δίδωμι(dídōmi, “to give”). Doublet of doos.
dose (plural doses)
etymonline
dose (n.)
early 15c., "the giving of medicine (in a specified amount or at a stated time)," from Old French dose (15c.) or directly from Medieval Latin dosis, from Greek dosis "a portion prescribed," literally "a giving," used by Galen and other Greek physicians to mean an amount of medicine, from stem of didonai "to give" (from PIE root *do- "to give").
Meaning "quantity of medicine given or prescribed" is from c. 1600. Extended sense, in reference to anything given to be "swallowed," literal or figurative, is from c. 1600. Slang meaning "a case of venereal disease" is by 1914.
dose (v.)
1650s, "give medicine to;" 1713, "administer in doses," from dose (n.). Related: Dosed; dosing.
