Lewis & Short

2. lābrum, i, n. [for lavabrum, q. v.],

  1. I. a basin, a tub for bathing; a vat for treading out grapes: labrum si in balineo non est, Cic. Fam. 14, 20: marmoreo labro aqua exundat, Plin. Ep. 5, 6, 20: splendentia, Verg. A. 12, 417: aëna, id. ib. 8, 22: marmorea duo labra ante fornicem posuit, Liv. 37, 3, 7: unda labris nitentibus instat, Stat. S. 1, 5, 49: eluacrum, Cato, R. R. 11: lupinarium, id. ib.: olearium, id. ib. 13; Col. 12, 50, 10 sq.; cf.: spumat plenis vindemia labris, in the full vats or vessels, Verg. G. 2, 6; of a tub or basin for bathing, Vitr. 5, 10, 4; of a fountain, Dig. 19, 1, 15.
  2. II. Poet. transf., a bath: nec Dryades, nec nos videamus labra Dianae, Ov. F. 4, 761; cf. id. Ib. 481; id. H. 21, 178.