Lewis & Short

per-fūsĭo, ōnis, f. [perfundo].

  1. I. In gen., a pouring over or upon, a wetting, moistening (post-Aug.). perfusio corporis ex aquā calidā, Cels. 4, 8; Plin. 18, 7, 14, § 74.
    In plur.: alarum perfusiones, Plin. 23, 9, 82, § 164.
  2. II. Esp., baptism, Lact. 4, 15, 1.