Lewis & Short

undo, āvi, ātum, 1, v. n. and a. [unda].

  1. I. Neutr., to rise in waves or surges, to throw up waves, to surge, swell (poet. and in postAug. prose).
    1. A. Lit.: undantem salum, Enn. ap. Non. 223, 24 (Trag. v. 226 Vahl.); cf.: undanti in freto, Att. ap. Cic. N. D. 2, 35, 89: solet aestus aequinoctialis … undare, Sen. Q. N. 3, 28, 6: ad caelum undabat vortex, Verg. A. 12, 673: aëna undantia flammis, id. ib. 6, 218.
    2. B. Transf.
      1. 1. To overflow with, be full of, abound in any thing, = abundare: regio Undat equis floretque viris, Val. Fl. 1, 539: vultus sanguine, Stat. Th. 1, 449: silva favis, Claud. Rapt. Pros. 3, 25: ima (aedium) viris, id. VI. Cons. Hon. 545.
      2. 2. To wave, undulate: vidimus undantem ruptis fornacibus Aetnam, Verg. G. 1, 472: undantes flammae, Sil. 9, 446: undante fumo, Sen. Troad. 19: undans buxo Cytorus, Verg. G. 2, 437: undans chlamys, Plaut. Ep. 3, 3, 55: undantes habenae, waving, flowing, hanging loosely, Verg. A. 12, 471; so, undantia lora, id. ib. 5, 146: ipsa (puella) decenter undabat, undulated, App. M. 2, p. 117, 38.
    3. C. Trop., to waver, fluctuate, be agitated: undans curis, Val. Fl. 5, 304: undantes spumis furialibus irae, Claud. in Ruf. 1, 76.
  2. II. Act. (very rare), to overflow, inundate, deluge: sanguine campos, Stat. Achill. 1, 87: sinus cruore, Claud. in Ruf. 2, 67.
    P. a.: undātus, a, um, in a wavy or wave-like form: concharum genera imbricatim undata, cancellatim reticulata, Plin. 9, 33, 52, § 103.
    Hence, undan-ter, adv., in a waving manner, like waves: capillus undanter fluens, App. M. 2, p. 122, 7 (al. fluenter undans): evomere talia, Mart. Cap. 2, § 138.