vi to become fossil.
2. fossilize ·vi to become antiquated, rigid, or fixed, beyond the influence of change or progress.
3. fossilize ·vt to convert into a fossil; to petrify; as, to fossilize bones or wood.
4. fossilize ·vt to cause to become antiquated, rigid, or fixed, as by fossilization; to mummify; to deaden.