unquenchable

The word 'unquenchable' is built upon the Old English verb 'cwencan,' which meant to extinguish or put out, as with fire or light. This core meaning naturally extended to the figurative sense of satisfying or suppressing a thirst or desire. The addition of the negative prefix 'un-' creates the meaning "not able to be extinguished or satisfied." Finally, the suffix '-able,' derived from Latin '-abilis,' transforms the concept into an adjective describing a permanent, inherent quality. Thus, the literal morphemes combine to form a word that powerfully describes something, typically a desire or feeling, that is incapable of being subdued or fulfilled.