TEMPERAMENTAL

erratic, temperamental

(adjective) 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

moody, temperamental

(adjective) subject to sharply varying moods; “a temperamental opera singer”

temperamental

(adjective) relating to or caused by temperament; “temperamental indifference to neatness”; “temperamental peculiarities”

Source: WordNet® 3.1

Etymology

Adjective

temperamental (comparative more temperamental, superlative most temperamental)

(notcomp) Of, related to, or caused by temperament.

Subject to changing and unpredictable emotional states; moody, capricious; sometimes used figuratively to describe user-unfriendly or unstable machines or software that are either complicated and/or have poorly written instructions and are subsequently difficult to operate.

Source: Wiktionary

Tem`per*a*men"tal, a.

Definition: Of or pertaining to temperament; constitutional. [R.] Sir T. Browne.

Source: Webster’s Unabridged Dictionary 1913 Edition