Webster's Revised Unabridged Dictionary · 1913

Fossilize

Fossilize , transitive verb

[Compare French fossiliser.]

1.
To convert into a fossil; to petrify; as, to fossilize bones or wood.
2.
To cause to become antiquated, rigid, or fixed, as by fossilization; to mummify; to deaden.
Ten layers of birthdays on a woman's head Are apt to fossilize her girlish mirth. — Mrs. Browning

Fossilize , intransitive verb

1.
To become fossil.
2.
To become antiquated, rigid, or fixed, beyond the influence of change or progress.