Lewis & Short

densus, a, um, adj. [kindred with δασύς, δαυλός (i. e. δασυλός); cf. Lat. dumus, old form dusmus, and dumetum], thick, dense, i. e. consisting of parts crowded together. opp. to rarus (on the contrary, crassus, thick, is opp. to thin, fluid; and spissus, close, compact, with the predominant idea of impenetrability; cf. also: angustus, artus, solidus—class. and freq., esp. in poets and historians; in Cic. very rare).

  1. I. Lit.
      1. 1. In space: ne dum variantia rerum Tanta queat densis rarisque ex ignibus esse, Lucr. 1, 654; cf. Verg. G. 1, 419 (for which densatus et laxatus aër, Quint. 5, 9, 16); and: (terra) Rara sit an supra morem si densa requiras … Densa magis Cereri, rarissima quaeque Lyaeo, Verg. G. 2, 227 sq.: densa et glutinosa terra, Col. praef. § 24: silva, poëta ap. Cic. Att. 12, 15; cf.: densiores silvae, Caes. B. G. 3, 29, 2: densissimae silvae, id. ib. 4, 38, 3: lucus densissimae opacitatis, Front. Strat. 1, 11, 10: denso corpore nubes, Lucr. 6, 361; cf.: denso agmine, id. 6, 100; so, agmen (sc. navium), Verg. A. 5, 834: densum umeris vulgus, Hor. Od. 2, 13, 32 et saep.: tunicae, Plin. 11, 23, 27, § 77: zmaragdi, id. 37, 5, 18, § 68: litus, sandy, Ov. M. 2, 576; cf. Verg. G. 2, 275: aequor, i. e. frozen. Luc. 2, 640: aër, Hor. Od. 2, 7, 14; cf. caelum, Cels. 1 praef.; 3, 22: nimbi, Ov. M. 1, 269: caligo, Verg. A. 12, 466; cf.: densissima nox, pitch-dark night, Ov. M. 15, 31: umbra, Catull. 65, 13; Hor. Od. 1, 7, 20 et saep.
        Without distinction, corresp. with crassus, Lucr. 6, 246 al.
        1. b. Poet. with abl., thickly set with, covered with, full of: loca silvestribus sepibus densa, poëta ap. Cic. N. D. 1, 42 fin.; cf.: specus virgis ac vimine, Ov. M. 3, 29: vallis piceis et acuta cupressu, id. ib. 3, 155: Thybris verticibus, id. F. 6, 502: ficus pomis, id. ib. 2, 253: corpora setis, id. M. 13, 846; cf. id. Am. 3, 1, 32: femina crinibus emptis, id. A. A. 3, 165: funale lampadibus, id. M. 12, 247: trames caligine opaca (coupled with obscurus), id. ib. 10, 54 et saep.
    1. B. Transf., of the parts themselves which are crowded together, thick, close, set close: superiorem partem collis densissimis castris (sc. trinis) compleverant, pitched very near together, Caes. B. G. 7, 46, 3: sepes, id. ib. 2, 22: frutices, Ov. M. 1, 122: ilex, id. F. 2, 165 et saep.: hostes, Verg. A. 2, 511: ministri, id. M. 2, 717: densior suboles, Verg. G. 3, 308: dens (pectinis), Tib. 1, 9, 68: comae, Ov. Am. 1, 14, 42; cf. pilae, id. F. 2, 348 et saep.
      Poet.: densorum turba malorum, Ov. Tr. 5, 6, 41.
      1. 2. In time, of things which take place in close succession, thick, frequent, continuous (mostly poet.): ictus, Verg. A. 5, 459; cf. plagae, Hor. Od. 3, 5, 31: Aquilo, strong, powerful, Verg. G. 3, 196: silentia, deep, profound, Val. Fl. 3, 604: amores, Verg. G. 4, 347: pericula, Ov. P. 4, 7, 15: usus, id. ib. 4, 3, 15: ictus, Amm. 15, 5, 31.
  2. II. Trop. of speech, condensed, concise: vox atrox in ira, et aspera ac densa, coarse, Quint. 11, 3, 63: tanta vis in eo (sc. Demosthene) tam densa omnia, etc., id. 10, 1, 76; cf. transf. to the writer himself: densior ille (sc. Demosthenes), hic (sc. Cicero) copiosior, ib. § 106: densus et brevis et semper instans sibi Thucydides, ib. § 73: (Euripides) sententiis densus, ib. § 68.
    Adv.: densē (very rare).
      1. 1. In space, thickly, closely, close together: caesae alni, Plin. 16, 37, 67, § 173: calcatum quam densissime, Vitr. 5, 12 med.: milites densius se commovebant, Amm. 24, 6, 8.
      2. 2. (Acc. to no. I. B. 2.) In time, frequently, rapidly, one after the other: quod in perpetuitate dicendi eluceat aliquando, idem apud alios densius, apud alios fortasse rarius, Cic. Or. 2, 7: nulla tamen subeunt mihi tempora densius istis, Ov. P. 1, 9, 11: replicatis quaestionibus dense, Amm. 29, 3 fin.