meth

Etymology 1

Clipping of methamphetamine.

noun

1. (informal) Methamphetamine, especially in the form of the crystalline hydrochloride.

Etymology 2

Clipping of methadone.

noun

1. (informal) Methadone.
   Dunno why you want to try and make last any longer than it already does. Meth has to be the single most wicked shit I ever involved myself with. But as far as what it actually does, your best bet would be to trot down to the local library and look it up. 1998-11-14, Markus, “Re: METH”, in alt.recovery (Usenet)

Etymology 3

From meths or methylated spirits, as stereotypically drunk by tramps.

noun

1. (derogatory, Liverpool, Manchester) A tramp.

Etymology 4

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

noun

1. A spiced mead, originally from Wales.
   The Russians, Swedes, Danes, and those of Northern Inhabitants, exceed all the rest, having made the drinking of Brandy, Aqua Vitae, Hydromel, Beer, Mum, Meth, and other Liquors in great quantitites, so familiar to them, that they usually drink our countrymen to death. 1678, John Worlidge, Vinetum Britannicum, or a Treatise of Cider, 3rd edit.

Etymology 5

Clipping of method, which see.

noun

1. (slang) Marijuana.