Lewis & Short

princĭpor, āri, v. dep. a. [princeps], to rule (eccl. Lat.).

  1. I. Lit.: principari in nationes, Lact. 14, 13, 19: prolem … principibus principantem, Sid. Carm. 9, 47; 23, 90.
  2. II. Transf.: sanguis in nostro corpore principatur, Aug. Prophet. 6.