WordNet sense 1 (subject to change):

changeable, unsettled

WordNet sense 2 (liable to or capable of change):

variable

WordNet sense 3 (not established or confirmed):

unsealed

WordNet sense 4 (not worthy of reliance or trust):

unreliable

WordNet sense 5 (acting with uncertainty or hesitance or lack of confidence):

hesitant

WordNet sense 6 (fraught with uncertainty or doubt):

doubtful, dubious

WordNet sense 7 (uncertain or unable to decide about what course to follow):

ambivalent

WordNet sense 8 (lacking or indicating lack of confidence or assurance):

unsure, incertain

WordNet sense 9 (not decided or not known):

indefinite

WordNet sense 10 (having more than one possible meaning):

ambiguous