Lewis & Short

frăces, um (sing. form FRAX; v. the foll.), m. [kindr. with FRAG, frango; cf. fragosus; lit., broken bits, fragments; hence], grounds or dregs of oil: FRAX τρυγία γάρου; fraces ἐλαίου τρυγία: ὑπόστασις ἐλαίου; fracere ἐξίστασθαι; fracidus ὑπέρωρος, Gloss. Philox.: oleum quam diutissime in amurca et in fracibus erit, tam deterrimum erit, Cato, R. R. 64 fin.; 66 fin.; Col. 6, 13, 3; Plin. 15, 6, 6, § 21 sq. al.; Vitr. 7, 1; Grat. Cyneg. 474.