Lewis & Short

hĭulcus, a, um, adj. [hio], gaping, split, cleft, opened, open.

  1. I. Lit. (only poet.): ubi hiulca siti findit Canis aestifer arva, Verg. G. 2, 353: Aegyptus, Stat. Th. 4, 708: venae fluminis, id. ib. 9, 450: juga montis Tauri, Sol. 38 fin.: nubes, Claud. Cons. Prob. et Olybr. 206: nimbi, id. Rapt. Pros. 2, 230: vulnus, Sid. Ep. 6, 7: ova, Claud. III. Cons. Hon. 4 praef.: mucro, i. e. ungues ferrei, Prud. στεφ. 10, 452: ictus, id. ib. 5, 113.
    1. * B. Poet. transf., act., cleaving, destroying: fulmen, Stat. Th. 1, 26.
  2. II. Trop.
    1. A. Of speech, gaping, not well connected, forming a hiatus (class.): struere verba sic, ut neve asper eorum concursus neve hiulcus sit, sed quodammodo coagmentatus et levis, Cic. de Or. 3, 43, 171; cf.: hiulcae voces, id. Or. 44, 150: nonnumquam hiulca etiam decent, Quint. 9, 4, 36.
    2. * B. Eager, longing for any thing: gens, Plaut. Trin. 2, 2, 9.
      * Adv.: hiulcē (acc. to II. A.), of speech, in a gaping manner, with a hiatus: non aspere, non vaste, non rustice, non hiulce, sed presse et aequabiliter et leniter (loqui), Cic. de Or. 3, 12, 45.