Lewis & Short

perfĭcus, a, um, adj. [perficio],

  1. I. completing, perfecting (poet.): natura, Lucr. 2, 1116.
  2. II. Subst.: Perfĭca, ae, f., the finishing or completing goddess, she that perfects: natura creatrix, Lucr. 2, 1116.
    Of the goddess supposed to preside over sexual indulgence, Arn. 4, 131.