The Oxford Thesaurus An A-Z Dictionary of Synonyms - temperamentaladj.

1) moody, sensitive, touchy, hypersensitive, volatile, irascible, irritable, petulant, testy, short-tempered, hot-tempered, hotheaded, hot-blooded, excitable, explosive, on a short fuse or US fuze, capricious, impatient, bad-humoured, curt, brusque, short, gruff, bluff, curmudgeonly, waspish, snappish, peevish, crabby, crabbed, grumpy, huffish, huffy, crotchety, US cranky, Colloq grouchy: He's not usually temperamental - must be something he ate. 2) erratic, uneven, unreliable, inconsistent, undependable, unpredictable: That car of mine is getting temperamental in its old age.