Fúnditor, pen. cor. funditôris, m. g. Cæs. A slinger: one vsing a sling.Fundibularius. Idem.
Lewis and Short: Latin dictionary
fundĭtor, ōris, m. [funda], one who fights with a sling, a slinger, sfendoni/ths, a sort of light-armed soldier (cf.: jaculator, sagittarius), Caes. B. G. 2, 7, 1; 2, 10, 1; 2, 19, 4; 2, 24, 4 et saep.; Sall. J. 46, 7; 49, 6 al.