fossilize v.

1610s, "any thing dug up;" 1650s (adj.) "obtained by digging" (of coal, salt, etc.), from French fossile (16c.), from Latin fossilis "dug up," from fossus, past participle of fodere "to dig," from PIE root *bhedh- "to dig, pierce."

Restricted noun sense of "geological remains of a plant or animal" is from 1736 (the adjective in the sense "pertaining to fossils" is from 1660s); slang meaning "old person" first recorded 1859. Fossil fuel (1833) preserves the earlier, broader sense.

Ikhthes oryktoi "fossil fishes" were known to the Greeks, along with fossil shells on mountaintops and fossil "seaweed" in Sicilian quarries. They sometimes were taken as evidence of changing sea levels.

word-forming element used to make verbs, Middle English -isen, from Old French -iser/-izer, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.

The variation of -ize and -ise began in Old French and Middle English, perhaps aided by a few words (such as surprise, see below) where the ending is French or Latin, not Greek. With the classical revival, English partially reverted to the correct Greek -z- spelling from late 16c. But the 1694 edition of the authoritative French Academy dictionary standardized the spellings as -s-, which influenced English.

In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the Times of London, and Fowler, -ise remains dominant. Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise). American English has always favored -ize. The spelling variation involves about 200 English verbs.

noun of action from fossilize.