Lewis & Short

rĕcī̆prŏcus, a, um, adj. [perh. from reque proque, back and forth].

  1. I. Lit., turning back the same way, returning, receding (poet. and in post-Aug. prose): apud Attium: reciproca tendens nervo equino concita Tela; reciproca est, quom unde quid profectum, redit eo, flung back, Varr. L. L. 7, § 80 Müll. (an imitation of the Homeric παλίντονα τόξα).
    Esp. freq. of receding waters: vadosum ac reciprocum mare, Plin. 5, 4, 4, § 26: amnes, id. 9, 57, 83, § 176; 16, 36, 66, § 169; Tac. A. 1, 70; and of the ebb and flow, Plin. 2, 27, 99, § 213; hence, poet., an epithet of the sea, Sil. 3, 60.
  2. II. Trop., alternating, reciprocal, etc.: voces, reverberating echoes, Plin. 2, 44, 44, § 115: argumenta, retorted, Gr. ἀντιστρέφοντα, Gell. 5, 10, 2: ars, alternaling, reciprocal, Plin. 11, 2, 1, § 3; cf. taliones, Gell. 20, 1, 35: vices pugnandi, id. 15, 18, 3: epistulae, Hier. Ep. 5, 1: munus, Aus. Ep. 7.
      1. 2. In gram., pronomen, a reciprocal pronoun, as sibi, se, Prisc. p. 939 P.: versus, which has the same metre when the order of words is reversed, e. g. Verg. A. 1, 8 (4); Diom. p. 515 P.
        Hence, adv.: rĕcī̆prŏcē, alternately, to and fro (cf.: invicem, vicissim): fluere, Varr. R. R. 3, 17, 9.
        Transf., conversely, Prisc. 1142 P.