Lewis & Short

āmento, āvi, ātum, 1, v. a. [amentum].

  1. I. Lit., to furnish with a strap or thong; esp. of the javelin, to the middle of which a strap was fastened, so that it might be thrown with greater force (very rare; only twice in Cic.): hastae amentatae, Cic. Brut. 78, 271.
    Trop., of discourse: amentatae hastae (i. e. apta et parata argumenta), Cic. de Or. 1, 57, 242 (so Juv. sagittae and jaculator, q. v.).
  2. II. Transf., poet., to hurl or dart the javelin by means of a thong: cum jaculum parvā Libysamentavit habenā, * Luc. 6, 221.
    And of the wind, which gives an impetus to motion, as a thong to the dart: amentante Noto, Sil. 14, 422.