Lewis & Short

vădum, i, n. (masc. collat form, vă-dus, i, Varr. ap. Serv. Verg. A. 1, 111; Sall. H. 1, 68 Dietsch) [cf. the root BA, βαίνω, whence, also, vado; hence, that through which one can go], a shallow place in water, a shallow, shoal, ford.

  1. I. Lit.
      1. 1. Sing.: Rhodanus nonnullis locis vado transitur, Caes. B. G. 1, 6; 5, 58; 7, 55: vadum in flumine efficere, id. B. C. 1, 61: vadum fluminis temptare, si transire possent, id. ib. 1, 83: exercitum vado transducere, id. ib. 3, 37: vado flumen penetrare, Tac. A. 2, 68: vado superari amnis non poterat, Liv. 38, 13, 9; 38, 18, 7: piscis qui vivit in vado, Cels. 2, 18: amnis incerto vado, Tac. A. 12, 33.
      2. 2. Piur., so esp. of a shallow place where a river is crossed, a ford: ibi vadis repertis partem suarum copiarum transducere conati sunt, Caes. B. G. 2, 9; 1, 8; 3, 13; Liv. 26, 45, 8; 31, 1, 5; Tac. A. 2, 23; id. H. 4, 27; Lucr. 1, 200; Ov. M. 1, 370; 3, 19.
        Also of shallows, as dangerous in navigation: mystica ad dextram vada Praetervecti, Att. ap. Varr. L. L. 7, 19 Müll. (Trag. Rel. v. 687 Rib.): brevia, Verg. A. 5, 221: caeca, id. ib. 1, 536: dura saxis Lilybeia caecis, id. ib. 3, 706; cf.: Nessus, scitus vadorum, Ov. M. 9, 108.
    1. B. Transf.
      1. 1. A body of water, a sea, stream, etc. (poet.): longā sulcant vada salsa carinā, Verg. A. 5, 158; 7, 198; Cat. 64, 58: si tamen Non tangenda rates transiliunt vada, Hor. C. 1, 3, 24; Ov. P. 4, 9, 2; Sen. Hippol. 181 al.
      2. 2. The bottom of a body of water, the depths (poet. and in post-Aug. prose): saxa Vadis levata, Hor. Epod. 16, 26; Plin. 3, praef. § 4: ostrea capta solido vado, id. 32, 6, 21, § 59: sedit limoso pressa carina vado, Ov. F. 4, 300.
      3. 3. The bottom of a well, Phaedr. 4, 9, 12; Plin. 31, 3, 23, § 39.
  2. II. Trop.
    1. A. Of shallow water, as a place of safety to the swimmer: haec propemodum jam esse in vado salutis res videtur, i. e. in safety, Plaut. Aul. 4, 10, 73: at in vado’st: jam facile enabit, id. Rud. 1, 2, 81: omnis res est jam in vado, Ter. And. 5, 2, 4.
    2. B. Of shallows, as dangerous to the mariner: emersisse jam e vadis et scopulos praetervecta videtur oratio mea, Cic. Cael. 21, 51: cera vadum tentet, rasis infusa tabellis, explore the way, i. e. make a first attempt, Ov. A. A. 1, 437.