Lewis & Short

per-callesco, callŭi, 3, v. inch. n. and a.

  1. * I. Neutr., to become very hardened, very callous: civitatis patientia percalluerat, Cic. Mil. 28, 76.
  2. II. Act., to get a good knowledge of; in perf., to be well acquainted with, to know well, be well versed in: usum rerum, Cic. de Or. 2, 34, 137; so, disciplinas Stoicas et dialecticas, Gell. 1, 22, 7: leges, id. 20, 1, 20: quinque et viginti gentium linguas, id. 17, 17, 2.