"a letting loose, freedom from self-restraint, surrender to natural impulses," by 1822 as a French word in English (it remained in italics or quotation marks through much of the 19c.; the naturalized abandonment in this sense was attempted from 1834), from a sense in French abandon "abandonment; permission" (12c.), from abandonner "to surrender, release" (see abandon (v.)).

The noun was borrowed earlier (c. 1400) from Old French in a sense "(someone's) control;" and compare Middle English adverbial phrase at abandon, i.e. "recklessly," attested from late 14c. In Old French, the past-participle adjective abandoné came to mean "zealous, eager, unreserved."

late 14c., "reduce in rank, etc.," from Old French abaissier "diminish, make lower in value or status; lower oneself" (12c.), literally "bend, lean down," from Vulgar Latin *ad bassiare "bring lower," from ad "to, toward" (see ad-) + Late Latin bassus "low, short" (see base (adj.)).

The form in English was altered 16c. by influence of base (adj.), making the word an exception to the rule that Old French verbs with stem -iss- enter English as -ish (comprehension might have played a role; earlier forms of abase often are identical with those of abash). Literal sense of "lower, depress" (late 15c.) is archaic or obsolete. Related: Abased; abasing.

early 15c., "embarrassment, dread, fear," from abase + -ment. Sense of "action of lowering in price" is mid-15c.; "action of lowering in rank" is 1560s; "condition of being abased" is from 1610s.

"perplex or embarrass by suddenly exciting the conscience, discomfit, make ashamed," late 14c., abaishen, earlier "lose one's composure, be upset" (early 14c.), from Old French esbaiss-, present stem of esbaer "lose one's composure, be startled, be stunned."

Originally, to put to confusion from any strong emotion, whether of fear, of wonder, shame, or admiration, but restricted in modern times to effect of shame. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]

The first element is es "out" (from Latin ex; see ex-). The second may be ba(y)er "to be open, gape" (if the notion is "gaping with astonishment"), possibly ultimately imitative of opening the lips. Middle English Compendium also compares Old French abaissier "bow, diminish, lower oneself" (source of abase). Related: Abashed; abashing. Bashful is a 16c. derivative.

c. 1300, abaten, "put an end to" (transitive); early 14c., "to grow less, diminish in power or influence" (intransitive); from Old French abatre "beat down, cast down, strike down; fell, destroy; abolish; reduce, lower" (Modern French abattre), from Vulgar Latin *abbatere, from Latin ad "to" (see ad-) + battuere "to beat" (see batter (v.)). The French literal sense of "to fell, slaughter" is in abatis and abattoir. Related: Abated; abating.

"act or state of being decreased or mitigated" in some way, mid-14c., from Old French abatement "overthrowing; reduction," from abatre "strike down; reduce" (see abate). Now mostly in the legal sense "destruction or removal of a nuisance, etc." (1520s).

"barricade defense made of felled trees with the branches angled outward," 1766, from French abatis, literally "things thrown down," from Old French abateiz "a casting down; slaughter, carnage" (12c.), from abatre "to beat down, throw down" (see abate).

"slaughterhouse for cows," 1820, from French abattre in its literal sense "to beat down, knock down, slaughter" (see abate) + suffix -oir, corresponding to Latin -orium, indicating "place where" (see -ory).

"not in the axis," 1847, from Latin ab "away from" (see ab-) + axile "of or belonging to an axis," from axis.

1520s, title given in France to "every one who wears an ecclesiastical dress" [Littré, quoted in OED], especially one having no assigned ecclesiastical duty but acting as a private tutor, etc., from French abbé (12c.), from Late Latin abbatem, accusative of abbas (see abbot). See Century Dictionary for distinctions.