Lewis & Short

ex-purgo, āvi, ātum, 1, v. a., to purge, cleanse, purify (class.).

  1. I. Lit.: dolabella quicquid emortuum est (trunci aut vitis), Col. 4, 24, 5: capisterio quicquid exteretur, id. 2, 9, 1: lepras, psoras, lichenas, lentigines, Plin. 23, 7, 64, § 126.
    Poet.: quae poterunt umquam satis expurgare (me) cicutae? i. e. to cure of poetic ecstasy, * Hor. Ep. 2, 2, 53: vetus fermentum, remove by cleansing, Vulg. 1 Cor. 5, 7.
    1. B. Trop.: expurgandus est sermo, * Cic. Brut. 74, 258.
  2. II. In partic., to clear from censure, to exculpate, vindicate, justify, excuse: me expurgare tibi volo, Plaut. Capt. 3, 4, 87; id. Mil. 2, 6, 17: sine me expurgem, Ter. And. 5, 3, 29; id. Hec. 5, 1, 16: non facile est expurgatu, id. ib. 2, 3, 4: sese parum expurgat, fails to vindicate, Sall. J. 69, 4: requirens objecta et expurgaturum asseverans, Tac. A. 16, 24: fidem consiliumque publicum, Gell. 7, 3, 5.
    Hence, P. a.: expurgātus, a, um, pure, clear; comp.: mens, Rufin. Orig. de Princ. 1, 1, 7.