Lewis & Short

denso, āvi, ātum, 1, and (less freq.) denseo, no perf., ētum, 2 (cf. Prisc. p. 837 P.; Charis. p. 233 ib. The MSS. often confound the two forms; densare appears to be critically certain in Liv. and Quint.; densere act. only denset, Verg. A. 11, 650; imp. densete, id. ib. 12, 264: densebant, Lucr. 5, 491: denserent, Tac. A. 2, 14; also active forms, Apul. Mund. p. 61, 13; Prud. Cath. 5, 53 al.; Sil. 4, 159; gerund, densendo, Lucr. 6, 482; pass. inf. parag. denserier, id. 1, 395; 647: densetur, Ov. M. 14, 369 al.: densentur, Hor. Od. 1, 28, 19; Verg. A. 7, 794, and other forms in Verg.; cf. Wagner, Verg. G. 1, 248.
See also addenso and condenso), v. a., to make thick, to press together, thicken (not in Cic. and Caes.).

  1. I. Lit.: Juppiter uvidus austris Densat, erant quae rara modo, et, quae densa, relaxat, Verg. G. 1, 419 (paraphrased: densatus et laxatus aer, Quint. 5, 9, 16); cf.: rarum pectine denset opus, Ov. F. 3, 820; Lucr. 1, 395: ignem, id. 1, 647; 656: omnia, id. 1, 662: agmina, Verg. A. 7, 794; cf. catervas, id. ib. 12, 264: ordines, Liv. 33, 8 fin.: scutis super capita densatis, Liv. 44, 9: funera, * Hor. Od. 1, 28, 19: glomerata corpus in unum densatur, Ov. M. 13, 605; cf.: (nubes) largos in imbres, Luc. 4, 76; Plin. 11, 41, 96, § 239: obtenta densantur nocte tenebrae, Verg. G. 1, 246; cf. Ov. M. 14, 369: hastilia, i. e. hurls thickly, Verg. A. 11, 650; cf. ictus, Tac. A. 2, 14: super acervum petrarum radices ejus densabuntur, Vulg. Job 8, 17.
    Absol.: (aestus) quasi densendo subtexit caerula nimbis, Lucr. 6, 482.
  2. II. Trop. of speech, to condense: instandum quibusdam in partibus et densanda oratio, Quint. 11, 3, 164: figuras, id. 9, 3, 101.