Medical
mid 17th century: via French from medieval Latin medicalis, from Latin medicus ‘physician’.
wiktionary
Borrowed from Middle French medical, from Medieval Latin medicālis, from Latin medicus. Replaced Old English lǣċe(“doctor (physician)”), which is cognate with Icelandic læknir(“doctor”).
etymonline
medical (adj.)
"pertaining or relating to the art or profession of healing or those who practice it," 1640s, from French médical, from Late Latin medicalis "of a physician," from Latin medicus "physician, surgeon, medical man" (n.); "healing, medicinal" (adj.), from medeor "to cure, heal," originally "know the best course for," from an early specialization of PIE root *med- "take appropriate measures" (source also of Avestan vi-mad- "physician"). "The meaning of medeor is based on a semantic shift from 'measure' to 'distribute a cure, heal'" [de Vaan]. The earlier adjective in English in this sense was medicinal. Related: Medically.
medical (n.)
1917, short for medical examination. Earlier it was colloquial for "a student or practitioner of medicine" (1823).
