unalterable

Unalterable is an adjective used to describe something that cannot be changed or modified. It conveys a sense of permanence or inevitability, and is often applied to facts, laws, or principles rather than opinions or preferences. In everyday use, it suggests that an outcome or condition is fixed beyond revision.

Etymology: The term derives from un- (not) + alterable (capable of being altered), with alterable from Latin alterare to change. The form has appeared in English since the early modern period. It is closely related to immutable, invariable, and fixed, though it emphasizes the impossibility of alteration rather than mere stability.

Usage: Unalterable is common in legal, philosophical, or scientific writing to characterize provisions, truths, or constants that are treated as fixed. For example, one might refer to an unalterable principle of physics or describe a contract clause as unalterable. In rhetorical use, it can colorfully stress that a matter will not change under any circumstance. In casual speech, however, speakers may instead say something is fixed or permanent.

Related terms include immutable, unmodifiable, fixed, and irrevocable, each with a distinct emphasis: immutable relates to inherent unchangeability; unmodifiable to the absence of practical ability to change; irrevocable to the impossibility of reversing a decision or action. Understanding these nuances helps prevent misapplication in precise contexts.