Lewis & Short

ex-erro, āre, v. n., to wander away (post-Aug. and very rare).

  1. I. Lit.: dexterque exerrat Arion (equus), Stat. Th. 6, 444; Anthol. Lat. 5, 172, 1; 6, 17, 22.
  2. II. Trop., to deviate, err: a via veritatis, Cypr. Ep. 1, 12; Vulg. Sap. 12, 12: mentibus, id. 2 Macc. 2, 2.