"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.
"one versed in the science of metaphysics," mid-15c., perhaps from Old French methafisicien (14c., Modern French métaphysicien), or from metaphysic on the model of physician. In later colloquial use "one who practices the mind-cure," 1881.
c. 1300, "store, treasure," from Old French garison "defense, protection, safety, security; crops, food; salvation; healing, recovery, cure" (Modern French guérison "cure, recovery, healing") from garir "take care of, protect, defend," from a Germanic source, from Proto-Germanic *war- "to protect, guard," from PIE root *wer- (4) "to cover."
Meaning "fortified stronghold" is from early 15c.; that of "body of troops in a fortress" is from mid-15c., a sense taken over from Middle English garnison "body of armed men stationed in a fort or town to guard it" (late 14c.), from Old French garnison "provision, munitions," from garnir "to furnish, provide" (see garnish (v.)).
early 14c., "recompense, reparation," a shortened form of amends. Sense of "a remedy, cure" (now obsolete) is from mid-14c., from mend (v.). Meaning "act of mending; a repaired hole or rip in fabric" is from 1888. Phrase on the mend "on the path to recovering from sickness, improving in condition" is attested by 1802.