Example: "An open question"
Example: "Some who had been on the fence came out in favor of the plan"
Example: "Undecided voters"
To reverse or recant (a previous decision).
A voter etc. who has not yet come to a decision.
Open and not yet settled or determined.
Example: "The question of man's destiny is still undecided."
Uncommitted, not having reached a decision.
Example: "The result of the election is in doubt because of a large number of undecided voters."