Lewis & Short

plūrālĭtas, ātis, f. [pluralis].

      1. 1. Plurality (opp. to unitas), Ambros. in Psa. 118, prol. § 2; plur., Boëth. Arithm. 1, 4.
      2. 2. Gram. t. t., the plural number, Charis. p. 50 P.