Lewis & Short

frăgōsus, a, um, adj. [fragor].

  1. I. (Acc. to fragor, I.) Apt to be broken, fragile (poet. and in post-Aug. prose).
    1. A. Lit.: fragosa putri corpore, Lucr. 2, 860.
      1. 2. Transf., rough, uneven: silvis horrentia saxa fragosis, Ov. M. 4, 778: mons, Grat. Cyneg. 527.
    2. B. Trop., of speech, uneven, unequal: fragosa atque interrupta oratio, Quint. 9, 4, 7: aures fragosis offenduntur, id. 9, 4, 116: versus, Diom. p. 499 P.
  2. II. (Acc. to fragor, II.) Crashing, rushing, roaring (poet.): medioque fragosus Dat sonitum saxis et torto vertice torrens, Verg. A. 7, 566: vada, Val. Fl. 2, 622: arx Maleae, id. 4, 261: lux, a rattling gleam (lightning), id. 2, 198: murmura leonum, Claud. II. Cons. Stil. 337: nares, Amm. 14, 6, 25.
    Hence, * adv.: fră-gōse (acc. to II.), with a crashing: (secures a ligno laricis) respuuntur et fragosius sidunt, aegrius revelluntur, Plin. 16, 10, 19, § 47.