Word of the Day:

: not capable of being annulled or voided or undone

After his father's untimely demise, which reeked of foul play, Prince Nikolai took to the throne as was his indefeasible right as the king's eldest son.

More example sentences

We acquired "indefeasible" in the mid-16th century by combining the English prefix "in-" ("not") with "defeasible," a word borrowed a century earlier from Anglo-French. "Defeasible" itself can be traced to an Old French verb meaning "to undo" or "to destroy." It's no surprise, then, that something indefeasible is essentially "un-undoable" or "indestructible." Another member of this family of words is "feasible," meaning "capable of being done or carried out." Ultimately, all three -- "indefeasible," "defeasible," and "feasible" -- can be traced back to the Latin verb "facere," meaning "to do."