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changeable: P. εὐμετάβολος, ὀξύρροπος; see changeable.
fickle: P. and V. ἔμπληκτος; see fickle.
unstable: P. and V. σφαλερός, Ar. and P. ἀστάθμητος.
perverse: P. and V. δύσκολος, δυσχερής, δυσάρεστος.