expurgation (n.) Look up expurgation at Dictionary.com
early 15c., "a cleansing from impurity," from Latin expurgationem (nominative expurgatio), noun of action from past participle stem of expurgare "to cleanse out, purge, purify," from ex- "out" (see ex-) + purgare "to purge" (see purge (v.)). Sense of "remove objectionable passages from a literary work" first recorded in English 1610s.