lit (n.2) Look up lit at Dictionary.com
colloquial shortening of literature, attested by 1850.
lit (adj.) Look up lit at Dictionary.com
"illuminated; afire," past participle adjective from light (v.2). Slang meaning "drunk" is recorded from 1914.
lit (n.1) Look up lit at Dictionary.com
"color, hue, dye," early 12c., from Old Norse litr "color, hue; the color of the sky at dawn or dusk," from Proto-Germanic *wlitiz (source also of Old Frisian wlite "exterior, form," Gothic *wlits "face, form"). The cognate Old English word was wlite "brightness; appearance, form, aspect; look, countenance; beauty, splendor," which seems to have been rare after c. 1400. Compare litmus.