Lewis & Short

circumactĭo, ōnis, f. [circumago].

  1. I. Lit., a turning around, revolving (very rare): solis, Vitr. 9, 9, 15; Mart. Cap. 8, § 885.
  2. * II. Trop., of discourse, a turning, turn, compass, Gell. 17, 20, 4.