Green’s Dictionary of Slang

snark v.

[snarky adj.]

1. (US campus/gay, also snark it up) to gossip, usu. maliciously; to criticize, to be grumpy.

[US]Eble Campus Sl. Apr. 7: snark – act snappy or grouchy or in a bad mood: ‘You’ve been snarking me all day.’.
[US]Allecto ‘Buddy Fuck’ 🌐 Which was how he ended up with Nick Carter’s number programmed into his cellphone, and a promise to ‘call and snark about boys, dude.’.
[US]Arizona Republic (Phoenix, AZ) 24 Apr. A9/2: He preferred snarky over smarmy [...] He wished I had ‘snarked it up’ even more.

2. (US, also snark off) to render irritated.

[US]Tampa Bay Times (St Petersburg, FL) 26 May 55/3: An instrumental blend of funk, R&B and jazz fusion sounds that snarked off purists.
[US]Tampa Bay Times (St Petersburg, FL) 22 Feb. 3E/1: Once a day, Oprah Winfrey snarked off my wife.

In derivatives

snarker (n.)

a carping critic.

[Aus]Truth (Brisbane) 25 July 12: [headline] First Battalion of Brisbane Blighters / Regiments of Rooks and Crooks / Sidelights on Snarker & Co.
Palm Beach Post (FL) 22 Mar. D017/1: The trouble with today’s snarkers [...] is that they ‘don’t have a coherent view of life [...] they’re mere opportunists’.