Lewis & Short

1. grossus, i, m. and f., an unripe fig, Cato, R. R. 94; Cels. 5, 12; Plin. 23, 7, 63, § 125; 17, 27, 43, § 254.

2. grossus, a, um, adj. [kindred with crassus], thick (late Lat.): virga, Cassiod. Hist. Eccl. 10, 33.
Comp.: vestis grossior, Sulp. Sev. Dal. 1, 21; Vulg. Ezech. 41, 25; 1 Reg. 12, 10; 2 Chron. 10, 10.
Sup., Cassiod. in Psa. 29, 12; cf.: grossus παχύς, Gloss. Philox.
Hence, adv. only comp.: gros-sĭus, more roughly: definire, Aug. de Duab. Anim. 11, 15.