Green’s Dictionary of Slang

1. (US) petty, mean, or stingy [snitch n.¹ (5)].

1911

L. Pound ‘A Second Word-List From Nebraska’ in DN III vii 547: Someone who is snitchy, i.e., petty, mean, or stingy.

2. (N.Z.) tetchy, ill-tempered [snitch n.² ].

2003

McGill Reed Dict. of N.Z. Sl.