What does indefeasible mean?
Indefeasible describes a right, principle, claim, or conclusion that cannot be defeated, disproved, invalidated, or cancelled. The word is especially common in legal and political language: an indefeasible right is protected from revocation or interference, while an indefeasible claim cannot be overturned through challenge or proof. Its force comes from the combination of “in-,” meaning not, and “feasible,” relating to being done or accomplished. In everyday use, the term can characterize anything presented as beyond question, though it may sound formal or deliberately absolute. For example, a constitution might protect judicial independence as an indefeasible principle. Because valid contracts and legal rights are often described this way, the word also appears in discussions of permanence, authority, and limits on the power of governments and institutions.
adjectiveNot capable of being defeated, disproved, or invalidated; impossible to overturn or cancel.
- Impossible to defeat, disprove, invalidate, or cancel.
"The court recognized an indefeasible right to access the public records."
"The organization's indefeasible independence is protected by the constitution."
"Historians questioned what had previously been regarded as an indefeasible conclusion."
In legal language, an indefeasible right is one that cannot simply be revoked—even powerful authorities remain bound by it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does indefeasible come from?
Indefeasible was formed in English using the prefix “in-,” meaning not, with “feasible” and the suffix “-ible,” yielding the sense “not defeasible” or “not capable of being overcome.” The underlying family comes through French from Latin facere, “to do” or “make,” the same broad root found in feasible, facility, and facilitate. Its development reflects the longstanding legal use of “defeasible” for rights or claims that can be challenged, annulled, or made void.
Related word forms
How indefeasible is actually used
Most common in formal and legal writing. It is sometimes used more broadly for principles, rights, claims, or conclusions that are considered permanent or beyond challenge. The word can sound emphatic, so writers should avoid using it where the underlying claim is merely disputed rather than genuinely immune to challenge.
Easily confused with indefeasible
Indefeasible means impossible to defeat or invalidate, whereas infeasible means impossible to carry out or achieve.
Indefeasible describes something that cannot be overturned, while defeasible describes something that can be challenged or invalidated.