Definition of defeasible in US English:



Law Philosophy
  • Open in principle to revision, valid objection, forfeiture, or annulment.

    • ‘They were not in any way, shape or form defeasible.’
    • ‘What they hold to be true is certain, not defeasible.’
    • ‘A second element of positive analogy between these two presumptions is that both are defeasible; and that they are, consequently, not to be identified with assumptions.’
    • ‘Each of these would-be reasons is defeasible and has been more than adequately seen off in argument during recent weeks.’
    • ‘In the jargon, this means that any scientific claim is defeasible, meaning it is in principle open to revision or rejection in the light of further disclosures, arguments, or evidence.’


Middle English: via Anglo-Norman French from the stem of Old French desfesant ‘undoing’ (see also defeasance).