Main entry: temperamental, erratic
Definition: likely to perform unpredictably
Usage: erratic winds are the bane of a sailor; a temperamental motor; sometimes it would start and sometimes it wouldn't; that beautiful but temperamental instrument the flute- Osbert Lancaster
Main entry: moody, temperamental
Definition: subject to sharply varying moods
Usage: a temperamental opera singer
Main entry: temperamental
Definition: relating to or caused by temperament
Usage: temperamental indifference to neatness; temperamental peculiarities