Lewis & Short

glăber, bra, brum, adj. [root γλαφ-, γλάφω, to hollow out, γλαφυρός; cf. scalpo],

  1. I. without hair, smooth, bald: oves glabrae quam haec est manus, Plaut. Trin. 2, 4, 140: si quem glabrum facere velis, Varr. R. R. 1, 2, 26: oves ventre glabro, id. ib. 2, 2, 6: colla boum, Col. 6, 14, 7: crure glaber, Mart. 12, 38, 4: glaber erat tamquam rien, Plaut. Fragm. ap. Fest. s. v. rienes, p. 276 and 277 Müll.: hordeum, Turran. ap. Plin. 18, 7, 15, § 75: tapete, Turp. ap. Non. 542, 18.
    Comp.: tu istum gallum glabriorem reddes mihi, quam volsus ludiu’st, Plaut. Aul. 2, 9, 6: maritus cucurbitā glabrior, App. M. 5, p. 163,
  2. II. Transf., as subst.: glăber, bri, m., a young (beardless) slave, favorite slave of the Romans, Cat. 61, 142; Phaedr. 4, 5, 22; Sen. Ep. 47; id. Brev. Vit. 12; Inscr. Orell. 694; 2911.