Learn That Word

Synonyms for Undecided (same or very similar meaning)

WordNet sense 1 (not brought to a conclusion; subject to further thought):
open, undetermined, unresolved

WordNet sense 2 (still in doubt):

WordNet sense 3 (characterized by indecision):
on the fence

WordNet sense 4 (characterized by lack of decision and firmness):

WordNet sense 5 (not bound or pledged):

From the ODE community, based on WordNetadd/edit