Lewis & Short

1. pollex, ĭcis, m. [polleo; cf.: pollex nomen ab eo, quod pollet, accepit, Atei. Cap’to ap. Macr. S. 7, 13, 11].

  1. I. Lit.
    1. A. The thumb: hominis digiti articulos habent ternos, pollex binos et digitis adversus universis flectitur, per se vero in obliquum porrigitur, crassior ceteris, huic minimus mensura par est, Plin. 11, 43, 99, § 244; Cic. Off. 3, 11, 46; Hor. Epod. 5, 48; id. C. 4, 6, 36; Ov. M. 4, 36; 8, 198; Verg. A. 11, 68.
      Connected with digitus (as a measure), Cato, R. R. 20: clavi digiti pollicis crassitudine, Caes. B. G. 3, 13.
      To close down the thumb (premere) was a sign of approbation; to extend it (vertere, convertere; pollex infestus), a sign of disapprobation, Plin. 28, 2, 5, § 25; Hor. Ep. 1, 18, 66; Juv. 3, 36; Prud. adv. Symm. 2, 1097; Stat. Th. 8, 26; Quint. 11, 3, 119; App. M. 2, p. 124, 3.
    2. B. The great toe, Plin. 7, 2, 2, § 20; 7, 53, 54, § 181; 28, 4, 9, § 42; Suet. Calig. 57: pollices manūs et pedis dextri, Vulg. Lev. 8, 24.
  2. II. Transf.
    1. A. The stump of a vine-branch left in pruning, = resex, Col. 4, 21, 3; 4, 24, 13; Plin. 14, 1, 3, § 14; 17, 22, 35, § 184.
    2. B. A knob or protuberance on the trunk of a tree, Plin. 13, 4, 7, § 29.

2. Pollex, ĭcis, m., the name of a slave of Cicero, Cic. Fam. 14, 6, 1; id. Att. 8, 5, 1; 13, 47, 1.
A lusus verbb. with 1. pollex, Cic. Att. 13, 46, 1.