Lewis & Short

frăcesco, fracŭi, 3, v. inch. n. [FRACEO; v. fraces and FRACEBUNT], to become soft or mellow, to rot, spoil: olea lecta si nimium diu fuit in acervis, caldore fracescit, et oleum foetidum fit, Varr. R. R. 55, 5 sq.; so, oleum, becomes rancid, Col. 1, 6, 18: (terram cretosam) sinito quatriduum fracescat; ubi bene fracuerit, rutro concidito, to become soft, tractable, Cato, R. R. 128.