adjective
1.
not stable, consistent, or predictable
was in very uncertain health
Synonyms: capricious, chancy, dicey, erratic, fluctuant, iffy, incalculable, unpredictable, whimsical; compare inconstant 1
Related Word: questionable, undependable, unsettled; fickle, inconstant, insecure, unstable, unsure; changeable, mutable, protean, variable; unexpectable, unforeseeable
Idioms: in a state of uncertainty, in suspense
2.
Synonyms: inconstant 1, capricious, changeable, fickle, lubricious, mercurial, temperamental, ticklish, unstable, volatile
3.
Synonyms: mutable 2, changeable, inconstant, shifty, slippery, unstable, unsteady, variable
4.
Synonyms: doubtful 1, borderline, dubious, indecisive, open, precarious, suspect, undecided, unsettled, unsure
Antonyms: certain
5.
Synonyms: moot , arguable, debatable, disputable, doubtful, dubious, mootable, problematic, questionable
Antonyms: certain
6.
Synonyms: obscure 3, ambiguous, amphibological, equivocal, sibylline, tenebrous, unclear, unexplicit, unintelligible, vague
7.
Synonyms: vacillating 2, faltering, halting, hesitant, irresolute, shilly-shallying, tentative, vacillatory, wiggle-waggle, wobbly
Idioms: at a loss
Antonyms: certain, set