"to cut or pinch off the burned part of a candle wick," mid-15c., from noun snoffe "burned part of a candle wick" (late 14c.), of unknown origin, perhaps related to snuff (v.2). The meaning "to die" is from 1865; that of "to kill" is from 1932; snuff-film, urban legend, is from 1975.
"draw in through the nose," 1520s, from Dutch or Flemish snuffen "to sniff, snuff," related to Dutch snuiven "to sniff," from Proto-Germanic *snuf- (cf. Middle High German snupfe, German Schnupfen "head-cold"), imitative of the sound of drawing air through the nose. Related: Snuffed; snuffing.
"powdered tobacco to be inhaled," 1680s, from Dutch or Flemish snuf, shortened form of snuftabak "snuff tobacco," from snuffen "to sniff, snuff" (see snuff (v.2)). The practice became fashionable in England c.1680. Snuff-box is attested from 1680s.