Merriam-Webster's Collegiate® Dictionary, 11th Edition
FOSSIL
I. adjective see: bed
Date: 1604
preserved from a past geologic age , being or resembling a fossil, of or relating to fossil fuel,
II. noun
Date: 1736
a remnant, impression, or trace of an organism of past geologic ages that has been preserved in the earth's crust,
2. a person whose views are outmoded ; fogy , something (as a theory) that has become rigidly fixed, an old word or word element preserved only by idiom (as fro in to and fro )