Meaning

noun an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant

originFrom metheglin, from Welsh meddyglyn, from meddyg (“medicinal”) (from Latin medicus) + llyn (“liquor”) (cognate with Irish lionn and Gaelic leann).

Etymology from Wiktionary, CC BY-SA 3.0