Green’s Dictionary of Slang

snark n.

[dial. snark, to fret, to grumble]

1. an unpleasant, prying person.

[UK]G. Jennings Poached Eggs and Pearls (1917) 16: lady mabel: Look at Lady Penzance giving him the glad eye! lady clara: The snark! She’ll watch me like a lynx.

2. an informer.

[US]Ragen & Finston World’s Toughest Prison 818: snark – An informer.

3. anger, irritation, tetchiness; sarcasm.

[US]D.H. Sterry Chicken (2003) 132: Some serious snark is clogging my pipes. I want to smash a mirror with a five-iron, crack a skull with a brick.
[US]J. Stahl Pain Killers 150: Trying to exude impassive blandness in the face of her snark.
[US]T. Robinson Hard Bounce [ebook] He didn’t bite at my snark.
B. McQuade Attack from Within 124: As a friend once told me, ‘Twitter is for snark’.