INCONSTANT

[in.con.stant] adj [ME, fr. MF, fr. L inconstant-, inconstans, fr. in- + constant-, constans constant] (15c): likely to change frequently without apparent or cogent reason -- in.con.stant.ly adv syn inconstant, fickle, capricious, mercurial, unstable mean lacking firmness or steadiness (as in purpose or devotion). inconstant implies an incapacity for steadiness and an inherent tendency to change "an inconstant friend". fickle suggests unreliability because of perverse changeability and incapacity for steadfastness "performers discover how fickle fans can be". capricious suggests motivation by sudden whim or fancy and stresses unpredictability "an utterly capricious critic". mercurial implies a rapid changeability in mood "made anxious by her boss's mercurial temperament". unstable implies an incapacity for remaining in a fixed position or steady course and applies esp. to a lack of emotional balance "too unstable to hold a job".