lăpĭdesco, ĕre, v. inch. n. [lapis], to become stone, turn to stone, to petrify (Plinian): spongiae ipsae lapidescunt, Plin. 24, 13, 73, § 120: in balano lapidescit duritia, id. 16, 6, 8, § 21; 32, 2, 11, § 22.