Lewis & Short

mordax, ācis, adj. [mordeo], biting, given to biting, snappish (poet. and in postAug. prose).

  1. I. Lit.: canis, Plaut. Bacch. 5, 2, 27: equus, Labeo ap. Gell. 4, 2: asinus, App. M. 8, p. 213 init.: Memmius, Auct. ap. Cic. de Or. 2, 59, 240.
    Poet.: fibula, Sid. Carm. 5, 18.
    1. B. Transf., stinging, sharp, biting, pungent: urtica, stinging, Ov. A. A. 2, 417: arista mordacior hordeo, Plin. 18, 7, 10, § 61: mordacissima marga, id. 17, 8, 4, § 45: mordaci icta ferro Pinus, biting, deepcutting, Hor. C. 4, 6, 9: pumex, Ov. A. A. 1, 506: pulvis, corrosive, Plin. 15, 29, 37, § 123: fel, biting, sharp, Ov. P. 3, 3, 106: acetum, sharp, pungent, Pers. 5, 86: sucus, Plin. 25, 8, 50, § 89.
  2. II. Trop., biting, disposed to bite.
    1. A. Of persons: Cynicus, biting, snarling, Hor. Ep. 1, 17, 18: lividus et mordax, id. S. 1, 4, 93.
    2. B. Of inanim. and abstr. things: carmen, Ov. Tr. 2, 563: invidia, Phaedr. 5 prol. 8: verum, Pers. 1, 107: sollicitudines, biting, carking, Hor. C. 1, 18, 4: belle interim subicitur pro eo, quod neges, aliud mordacius, a more stinging assertion, Quint. 6, 3, 74.
      Hence, adv.: mordācĭter, bitingly (poet. and postclass. prose), Macr. S. 7, 3, 8.
      Comp.: neque enim in nobis febris alias partes mordacius impellit, sed per omnia pari aequalitate discurrit, Sen. Q. N. 6, 15, 3: limā mordacius uti, more sharply, Ov. P. 1, 5, 19: scribere, Lact. 5, 2, 12.