unchangeable

The word "unchangeable" is a Modern English formation built from three distinct morphemes. The core, "change," entered English via Old French from the Late Latin verb cambiare, meaning "to exchange or barter," which itself may have a Celtic origin. This was then combined with the productive suffix "-able," from Latin -abilis, to create "changeable," meaning "capable of being altered." Finally, the Old English negative prefix "un-" was attached, a common Germanic element used to reverse the meaning. Thus, the word's literal construction of "not capable of being altered" directly and logically conveys its modern sense of permanence and immutability.