Pronunciation: (fos'ul),[key] —n. 1. any remains, impression, or trace of a living thing of a former geologic age, as a skeleton, footprint, etc.
2. a markedly outdated or old-fashioned person or thing.
3. a linguistic form that is archaic except in certain restricted contexts, as nonce in for the nonce, or that follows a rule or pattern that is no longer productive, as the sentence So be it.
—adj. 1. of the nature of a fossil: fossil insects. 2. belonging to a past epoch or discarded system; antiquated: a fossil approach to economics.