Lewis & Short

pĕractĭo, ōnis, f. [perago], a finishing, completion.

  1. I. Lit.: peccati, Hilar. in Psa. 118, 4, 8.
  2. II. Aetatis, transf. from the stage, qs. the last act of the drama, Cic. Sen. 23, 85 (cf. id. ib. 18, 64: fabulam aetatis peregisse, and 19, 70: peragenda fabula est).