1. vague or not clearly defined or stated (Freq. 8) - must you be so indefinite? - amorphous blots of color having vague and indefinite edges - he would not answer so indefinite a proposal • Ant: definite • Similar to: coy, indecisive, nebulous, unfixed, noncommittal, one • See Also: indistinct, unclear, undefined, vague • Derivationally related forms: indefiniteness, indefinity 2. not decided or not known - were indefinite about their plans - plans are indefinite • Similar to: uncertain • Derivationally related forms: indefiniteness