#1 temperamental a. relating to or caused by temperament; "temperamental indifference to neatness"; "temperamental peculiarities". wn
#2 temperamental s. [moody] subject to sharply varying moods; "a temperamental opera singer". wn
#3 temperamental s. [erratic] likely to perform unpredictably; "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. wn
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