Snappish, a.
1. Apt to snap at persons or things; eager to bite; as, a snapping cur.
2. Sharp in reply; apt to speak angrily or testily; easily provoked; tart; peevish. The taunting address of a snappish missanthrope. Jeffrey. -- Snap"pish*ly, adv. -- Snap"pish*ness, n.
Shades of meaning
Fernald has no entry of its own for snappish; he lists it under morose.
He lists it without comment; the entries above explain its neighbors.