Adjective conclusive has 3 senses
  1. conclusive - forming an end or termination; especially putting an end to doubt or question; "conclusive proof"; "the evidence is conclusive"
    inconclusive, equivocal, indeterminate, neck and neck, head-to-head, nip and tuck, nisi
  2. conclusive - final and deciding; "the conclusive reason"
    indecisive (indirect, via decisive)
  3. absolute, conclusive - expressing finality with no implication of possible change; "an absolute (or unequivocal) quarantee to respect the nation's authority"; "inability to make a conclusive (or unequivocal) refusal"
    Antonyms: equivocal, ambiguous (indirect, via unequivocal)