What is the meaning of the word irrevocable?

The word "irrevocable" refers to something that cannot be changed or reversed; it is final and binding. Therefore, the choice that directly aligns with this meaning is binding, as it conveys the idea that once a decision or agreement is made, it cannot be undone or altered. In legal contexts, for example, an irrevocable contract is one that obligates the parties in a way that cannot be changed without mutual consent.

The other options do not capture the essence of the term. "Fortunate" implies good luck or beneficial circumstances, which does not relate to the concept of something being unchangeable. "Unfeasible" suggests that something is not practical or achievable, and "indefinite" refers to something that lacks clear limits or boundaries, which also does not convey the permanence implied by "irrevocable." Thus, binding is the most accurate representation of what it means for something to be irrevocable.