"Warrantableness" refers to the quality or state of being justifiable or reasonable. Some synonyms for this term include justification, validity, soundness, defensibility, viability, and plausibility. Another possible synonym, depending on the context, could be "legitimacy." This refers to the quality of being lawful or in accordance with accepted standards or rules. In legal contexts, "admissibility" could also be used as a synonym for "warrantableness." This term refers to the quality of evidence being acceptable or able to be submitted as proof in a court of law. Overall, these synonymous terms suggest a conviction or confirmation of the truth or appropriateness of a particular idea or action.