"breach of faith or trust, base treachery," 1590s, from French perfidie (16c.), from Latin perfidia "faithlessness, falsehood, treachery," from perfidus "faithless," from phrase per fidem decipere "to deceive through trustingness," from per "through" (from PIE root *per- (1) "forward," hence "through") + fidem (nominative fides) "faith" (from PIE root *bheidh- "to trust, confide, persuade").

[C]ombinations of wickedness would overwhelm the world by the advantage which licentious principles afford, did not those who have long practiced perfidy grow faithless to each other. [Samuel Johnson, "Life of Waller"]

c. 1300, in expressions such as me is wo bigone "woe has beset me," from woe + begon, past participle of Middle English bego "to beset, surround, overwhelm," from Old English began "go over, traverse; inhabit, occupy; encompass, surround" (see be- + go (v.)). The verb is now obsolete, and its only survival is the fossilized past participle in this word.

late 14c., "envelop, surround; make cloudy or obscure," from Old French involver and directly from Latin involvere "envelop, surround, overwhelm," literally "roll into," from in- "in" (from PIE root *en "in") + volvere "to roll," from PIE root *wel- (3) "to turn, revolve." Mid-15c. as "concern oneself." Sense of "take in, include" first recorded c. 1600. Related: Involved; Involving.

Obscurest night involved the sky,

The Atlantic billows roared,

[Cowper, "The Castaway"]

late 14c., "convey from one place to another," from Old French transporter "carry or convey across; overwhelm (emotionally)" (14c.) or directly from Latin transportare "carry over, take across, convey, remove," from trans "beyond, across" (see trans-) + portare "to carry" (from PIE root *per- (2) "to lead, pass over"). Sense of "carry away with strong feelings" is first recorded c. 1500. Meaning "to carry away into banishment" is recorded from 1660s.

late 14c., mortifien, "to kill, destroy the life of," from Old French mortefiier "destroy, overwhelm, punish," from Late Latin mortificare "cause death, kill, put to death," literally "make dead," from mortificus "producing death," from Latin mors (genitive mortis) "death" (from PIE root *mer- "to rub away, harm," also "to die" and forming words referring to death and to beings subject to death) + combining form of facere "to make, to do" (from PIE root *dhe- "to set, put").

Religious sense of "subdue the flesh by abstinence and discipline" is attested from early 15c. Sense of "humiliate, chagrin, vex" is recorded by 1690s (compare mortification). Related: Mortified; mortifying.

Old English ofercuman "to reach, overtake, move or pass over," also "to conquer, prevail over, defeat in combat" (the Devil, evil spirits, sin, temptation, etc.), from ofer (see over) + cuman "to come" (see come (v.)). A common Germanic compound (Middle Dutch overkomen, Old High German ubarqueman, German überkommen).

In reference to mental or chemical force, "to overwhelm, render helpless," it is in late Old English. Meaning "to surmount (a difficulty or obstacle); succeed, be successful" is from c. 1200. The Civil Rights anthem "We Shall Overcome" was put together c. 1950s from the lyrics of Charles Tindley's spiritual "I'll Overcome Some Day" (1901) and the melody from the pre-Civil War spiritual "No More Auction Block for Me." Related: Overcame; overcoming.

late 14c., oppressen, "to press unduly upon or against, overburden, weigh down," also figuratively, "overwhelm overpower" (of sickness, grief, etc.); also "burden with cruel, unjust, or unreasonable restraints, treat with injustice or undue severity, keep down by an unjust exercise of power," from Old French opresser "oppress, afflict; torment, smother" (13c.), from Medieval Latin oppressare, frequentative of Latin opprimere "press against, press together, press down;" figuratively "crush, put down, subdue, prosecute relentlessly" (in Late Latin "to rape"), from assimilated form of ob "against" (see ob-) + premere "to press, hold fast, cover, crowd, compress" (from PIE root *per- (4) "to strike"). In Middle English also "to rape." Related: Oppressed; oppressing.

It is the due [external] restraint and not the moderation of rulers that constitutes a state of liberty; as the power to oppress, though never exercised, does a state of slavery. [St. George Tucker, "View of the Constitution of the United States," 1803]

early 14c., drounen, "suffocate by immersion in water or other fluid," also intransitive, "be suffocated by immersion (etc.)," also figurative, "to overwhelm or overpower by rising above as a flood," perhaps from an unrecorded variant of Old English druncnian (Middle English druncnen) "be swallowed up by water" (originally of ships as well as living things); at any rate it is probably from the base of drincan "to drink" (see drink (v.) and compare drench).

Or perhaps it is from Old Norse drukna "be drowned," which has at least influenced the modern form of the word, via North of England dialect. Related: Drowned; drowning. To drown (someone or something) out formerly was "to force to come out by influx of water;" in reference to sounds, by 1884.

c. 1300, snouen, "to fall as snow," from the noun, replacing Old English sniwan, which would have yielded modern snew (which lingered as a parallel form until 17c., longer in Yorkshire), from the Proto-Germanic source of snow (n.). The Old English verb is cognate with Middle Dutch sneuuwen, Dutch sneeuwen, Old Norse snjova, Swedish snöga.

Also þikke as snow þat snew,

Or al so hail þat stormes blew.

[Robert Mannyng of Brunne, transl. Wace's "Chronicle," c. 1330]

The transitive sense of "cause to snow" is by mid-14c. The figurative sense of "overwhelm; surround, cover, and imprison" (as heavy snows can bury livestock in the field) is 1880, American English, in phrase to snow (someone) under. Snow job "strong, persistent persuasion in a cause known to be dubious" (1943) is World War II armed forces slang, probably from the same image.

early 15c., "something that intimidates, an object of fear," from Old French terreur (14c.), from Latin terrorem (nominative terror) "great fear, dread, alarm, panic; object of fear, cause of alarm; terrible news," from terrere "fill with fear, frighten," from PIE root *tres- "to tremble" (see terrible).

From c. 1500 as "fear so great as to overwhelm the mind." Meaning "quality of causing dread" is attested from 1520s. Sense of "a person fancied as a source of terror" (often with deliberate exaggeration, as of a naughty child) is recorded from 1883. Terror bombing first recorded 1941, with reference to German air attack on Rotterdam. Terror-stricken is from 1831. The Reign of Terror in French history (March 1793-July 1794) was the period when the nation was ruled by a faction whose leaders made policy of killing by execution anyone deemed an impediment to their measures; so called in English from 1801. Old English words for "terror" included broga and egesa.