Meaning of temperamental

(adj) relating to or caused by temperament; "temperamental indifference to neatness"; "temperamental peculiarities"

subject to sharply varying moods; "a temperamental opera singer"

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