c. 1400, remedien, "effect a cure, cure;" also "put right, rectify, remove something evil from; give legal redress," from Old French remedier or directly from Latin remediare, from remedium (see remedy (n.)). Related: Remedied; remedying; remediless.
c. 1200, remedie, "means of counteracting sin or evil of any kind; cure for a vice or temptation;" late 14c., "a cure for a disease or disorder, medicine or process which restores health;" from Anglo-French remedie, Old French remede "remedy, cure" (12c., Modern French remède) and directly from Latin remedium "a cure, remedy, medicine, antidote, that which restores health," from re-, here perhaps an intensive prefix (or perhaps literally, "again;" see re-), + mederi "to heal" (from PIE root *med- "take appropriate measures").
Figurative use is from c. 1300. The meaning "legal redress; means for obtaining justice, redress, or compensation through a court" is by mid-15c.
c. 1400, "affording remedy or relief;" early 15c., of a disease, "able to be remedied, capable of being cured" (Chauliac), from Old French remédiable, from Latin remediabilis "that may be healed, curable," from stem of remediare "to heal, cure," from remedium "a cure, remedy" (see remedy (n.)).
early 15c., medicacioun, "medical treatment of a disease or wound," from Old French médication and directly from Latin medicationem (nominative medicatio) "healing, cure," noun of action from past-participle stem of medicare, medicari "to medicate, heal, cure" (poetic and Late Latin) from medicus "physician; healing" (from PIE root *med- "take appropriate measures"). Meaning "a medicinal substance or product" is by 1942.
Old English hælan "cure; save; make whole, sound and well," from Proto-Germanic *hailjan (source also of Old Saxon helian, Old Norse heila, Old Frisian hela, Dutch helen, German heilen, Gothic ga-hailjan "to heal, cure"), literally "to make whole" (from PIE *kailo- "whole;" see health). Intransitive sense from late 14c. Related: Healed; healing.
"admitting of medical treatment, curable, healable," 1610s, from Latin medicabilis "curable," from medicare, medicari "to medicate, heal, cure" (poetic and Late Latin) from medicus "physician, healing" (see medical (adj.)).