Etymology Probably from a dialectal variant of snithe (“sharp, cutting, cold”). See snithe (adjective). Alternatively, possibly a metathetic corruption of Middle English snythand (“piercing (the heart), cold, biting”, literally and figuratively). More at snithe (verb). Compare typologically cutting, Russian ко́лкий (kólkij) (akin to коло́ть (kolótʹ)).
1
Disparaging or derisive in an insinuative way.
Don't make snide remarks to me.
You write your snide bullshit from a dark room because that's what the angry do nowadays. I was nice to you, don't torture me for it.2010, Aaron Sorkin, The Social Network, spoken by Erica Albright (Rooney Mara):
2
Tricky; deceptive; false; spurious; contemptible.
Have nothing to do with snide goods; let it be known throughout the world that the farmers and dairymen, yea, and those engaged in other industries in the great State of Illinois, produce only the best of everything in their lines, and we will be the last to feel the effects of over-production.1890, Illinois State Dairymen's Association, Annual Report (volume 16, page 21)
I knew without studying them that the rings and the watch were snide, and the jewel a paste one; but they were damn fine counterfeits.2002, Sarah Waters, chapter 1, in Fingersmith, London: Virago, →ISBN, part 1, page 19:
Etymology Probably from a dialectal variant of snithe (“sharp, cutting, cold”). See snithe (adjective). Alternatively, possibly a metathetic corruption of Middle English snythand (“piercing (the heart), cold, biting”, literally and figuratively). More at snithe (verb). Compare typologically cutting, Russian ко́лкий (kólkij) (akin to коло́ть (kolótʹ)).
1
An underhanded, tricky person given to sharp practice; a sharper; a cheat.