Lewis & Short

sĭngŭlārĭus, a, um, adj. [singularis].

  1. I. Lit., single, separate, alone of its kind, peculiar (ante- and post-class. for the class. singularis; but cf. infra, adv.): homo unicā est naturā ac singulariā, Turp. ap. Non. 491, 2: litterae, i. e. abbreviations (syn. sigla), Gell. 17, 9, 2: catenae, perh. of a single ply, = simplices (or of a pound weight, i. e. light; opp. istas majores, v. 4; cf.: centenariae ballistae), Plaut. Capt. 1, 2, 3.
  2. * II. Remarkable, extraordinary, singular: homines singulariae velocitatis, Gell. 9, 4, 6.
    * Adv.: singŭlārĭē = singulariter: singularie pro singulariter quasi unice, Cicero, ut Maximus notat, Charis. p. 195 P.