Lewis & Short

prōcursĭo, ōnis, f. [procurro], a running forward, stepping forth.

  1. * I. Lit., of an orator: procursio opportuna, brevis, moderata, rara, Quint. 11, 3, 126.
  2. * II. Trop., a digression: necessaria post narrationem, Quint. 4, 3, 9.