Etymology: Either directly < purge v.¹, or perhaps < Middle French purge (French purge ) action of acquitting (a defendant) from a charge (1390), action of clearing oneself from a charge (1395), purgative treatment (1538; < purger purge v.¹). Compare Spanish purga (14th cent.), Italian purga (a1565), both earliest in sense 2. Compare earlier purgation n., purging n.Use in sense 3 with reference to the removal of undesirable individuals is apparently not paralleled in French until considerably later (1789). In 20th-cent. use with reference to Communist parties (see quots. 1933, 1974 at sense 3a) after Russian čistka (1921 or earlier in this sense).

Etymology: < Anglo-Norman purgir, porger, pourger, Anglo-Norman and Old French, Middle French purgier, Anglo-Norman and Old French, Middle French, French purger to purify (the soul) (end of the 12th cent.), to free (an object) from impurities (c1200, earliest with reference to threshing corn), to atone for (a sin) (early 13th cent.), to rid (the body) from impurities (c1265 in a medical context; 14th cent. used reflexively), to clear (a person, oneself) of an accusation or suspicion, to exculpate (oneself) (early 13th cent. or earlier in legal use; also used reflexively), to cancel or annul (an offence) (end of the 13th cent. or earlier in legal use in Anglo-Norman), to establish the innocence of (a person) by ordeal (end of the 13th cent. or earlier in legal use in Anglo-Norman), to establish the innocence of (a person) by an assertion on oath (beginning of the 14th cent. or earlier in legal use in Anglo-Norman), (of a liquid) to become clear (1680, used reflexively), to rid (an organization or party) of people regarded as undesirable (1789), to rid (a container) of a liquid (1923 or earlier) < classical Latin pūrgāre to free from impurities, clean, to remove by cleansing, to make ritually clean, to rid of undesirable persons, to expel from the body, to rid (the body) of waste or harmful matter, to absolve, clear, to wipe out or atone for by subsequent action, (reflexive) to apologize for an offence, (reflexive or passive, of a liquid) to become clear, in post-classical Latin also to make morally or spiritually pure (Vulgate), to clear by compurgation or ordeal (frequently from 12th cent. in British sources), variant (with elision of medial -i- ) of early Latin pūrigāre < pūrus pure adj. + -igāre , verbal suffix also seen in lītigāre litigate v. Compare Old Occitan, Occitan purgar (first half of the 12th cent.), Catalan purgar (14th cent.), Spanish purgar (first half of the 13th cent.), Portuguese purgar (13th cent.), Italian purgare (beginning of the 14th cent.), and also Middle Dutch purgēren (Dutch purgeeren ), Middle Low German pūrgēren , pūrgīren , Middle High German, German purgieren (now literary), Old Swedish, Swedish purgera (now rare; in Old Swedish only used reflexively). Compare spurge v.¹In sense 4b, which is apparently not paralleled in French until later (mid 16th cent. with reference to Jewish ceremonies of ritual purification), probably after classical Latin pūrgāre; compare also purgation n. 2. In Middle English prefixed and unprefixed forms of the past participle are attested (see y- prefix). The Middle English form purche (only attested in inflected forms) probably shows devoicing within English, rather than reflecting the rare Anglo-Norman variant purcher (a1415).

Etymology: Origin uncertain; the two quots. may show different words. In quot. a1430, perhaps a transmission error for burge v.; most of the manuscripts, including MS BL Add. 27944, read bringeþ bring v., but the edition by M. C. Seymour et al. (vol. 1, 1975) emends this on plausible semantic grounds to burgiþ . It is possible that quot. 1610 merely shows an intransitive use of purge v.¹Alternatively, it has been suggested that both instances represent transmission errors for an unattested verb *porge ( < classical Latin porgere, variant (with elision of the medial syllable) of porrigere to stretch out, extend: see porrect v.), but this is less likely, especially as regards quot. 1610.