c. 1300, purgen, "clear of a charge or suspicion," from Anglo-French purger, Old French purgier "wash, clean; refine, purify" morally or physically (12c., Modern French purger) and directly from Latin purgare "cleanse, make clean; purify," especially in reference to the body, "free from what is superfluous; remove, clear away," but also figuratively "refute, justify, vindicate," from Old Latin purigare, from purus "pure" (see pure) + root of agere "to set in motion, drive; to do, perform" (from PIE root *ag- "to drive, draw out or forth, move").
By mid-14c. as "to cleanse (a person or soul) from sin or moral defilement; to cleanse, clear, purify" (metal, etc.), also medicinally "to cleanse the body or digestive tract by a laxative, diuretic, or emetic." The figurative sense of "make ideal or pure, rid of objectionable elements or members" is by 1580s. Related: Purged; purging. The Latin verb is also the source of Spanish purgar, Italian purgare.
1560s, "that which purges," from purge (v.). Meaning "a purgative, an act of purging" is from 1590s. Political or social sense of "removal (from a governing body, party, army, etc.) of persons deemed undesirable" is by 1730 (in reference to Pride's Purge); modern use in reference to the Soviet Union is by 1933. The earliest sense of the word in English was "examination or interrogation in a legal court" (mid-15c.), a sense now obsolete even if the feeling persists.
late 14c., purgatif, in medicine, "having the property of cleansing by expelling impure matter from the body," from Old French purgatif (14c.) and directly from Late Latin purgativus, from purgat-, past-participle stem of Latin purgare "to cleanse, purify" (see purge (v.)). The noun is attested from early 15c., "a medicine that evacuates the intestines" (Old English medical texts have clænsungdrenc).
early 15c., expurgacion, "a cleansing from impurity," from Latin expurgationem (nominative expurgatio), noun of action from past-participle stem of expurgare "to cleanse out, purge, purify; clear from censure, vindicate, justify," from ex "out" (see ex-) + purgare "to purge" (see purge (v.)). Sense of "a removal of objectionable passages from a literary work" is recorded in English from 1610s. Related: Expurgatory.
late 14c., purgacioun, "purification from sin," also "discharge of waste; evacuation of evil humors by bloodletting, etc.," from Old French purgacion "a cleansing," medical or spiritual (12c., Modern French purgation) and directly from Latin purgationem (nominative purgatio) "a cleansing, purging," figuratively "an apology, justification," noun of action from past-participle stem of purgare "to cleanse, purify" (see purge (v.)).
"to chastise, punish," c. 1600, from Latin castigatus, past participle of castigare "to correct, set right; purify; chastise, punish," from castus "pure" (see caste) + agere "to do" (from PIE root *ag- "to drive, draw out or forth, move"). The notion behind the word is "make someone pure by correction or reproof." Compare purge (v.), from purus + agere. Related: Castigated; castigating; castigator; castigatory.
If thou didst put this soure cold habit on To castigate thy pride, 'twere well. [Shakespeare, "Timon" IV.iii (1607)]
c. 1200, purgatorie, "place or condition of temporal punishment for spiritual cleansing after death of souls dying penitent and destined ultimately for Heaven," from Old French purgatore, purgatoire and directly from Medieval Latin purgatorium (St. Bernard, early 12c.), in Latin, "means of cleansing," noun use of neuter of purgatorius (adj.) "purging, cleansing," from purgat-, past-participle stem of Latin purgare "to cleanse, purify" (see purge (v.)).
It is not considered as a place of probation ; for the ultimate salvation of those in purgatory is assured, and the impenitent are not received into purgatory. The souls in purgatory are supposed, however, to receive relief through the prayers of the faithful and through the sacrifice of the mass. The common belief in the Latin Church is that the purgatorial suffering is by fire ; the Greek Church, however, does not determine its nature. [Century Dictionary]
The figurative use for "state of mental or emotional suffering, expiation, etc." is from late 14c., originally especially when due to unrequited love, or, (seemingly paradoxically), marriage (e.g. Lydgate's wyfly purgatorye). In old New England it was used of narrow gorges and steep-sided ravines. Related: Purgatorial; purgatorian.
1620s, "to purge" (in anatomy), back-formation from expurgation or from Latin expurgatus, past participle of expurgare "to cleanse out, purge, purify." Related: Expurgated; expurgating. The earlier verb was simply expurge (late 15c.), from French expurger. Meaning "remove (something offensive or erroneous) from" is from 1670s.