mid-15c., "over-abundant," from Latin exuberantem (nominative exuberans) "superfluous; extraordinary," present participle of exuberare "be abundant, grow luxuriously," from ex, here probably "thoroughly" (see ex-), + uberare "be fruitful," related to uber "udder," from PIE root *eue-dh-r- (see udder). From 1510s as "growing luxuriantly;" figurative use, of affections, joyous emotions, etc., is by 1640s. Related: Exuberantly; exuberate; exuberating.
1630s, "an overflowing," from French exubérance (16c.), from Late Latin exuberantia "superabundance," abstract noun from exuberare "be abundant, grow luxuriously" (see exuberant). Usually figurative in English, especially of joy, happiness, etc. Exuberancy attested from 1610s.
"exuberant in growth or quantity," 1530s, from French luxuriant and directly from Latin luxuriantem (nominative luxurians), present participle of luxuriare "have to excess, grow profusely" (see luxuriate). Related: Luxuriantly.
1680s, from Latin effervescentem (nominative effervescens), present participle of effervescere "to boil up, boil over," from assimilated form of ex "out" (see ex-) + fervescere "begin to boil," from fervere "be hot, boil" (from PIE root *bhreu- "to boil, bubble, effervesce, burn"). Figurative meaning "exuberant" is from 1833.
"superfluous, exceeding what is natural or necessary," c. 1600, from Latin redundantem (nominative redundans), present participle of redundare, literally "overflow, pour over; be over-full;" figuratively "be in excess," from re- "again" (see re-) + undare "rise in waves," from unda "a wave" (from PIE *unda-, nasalized form of root *wed- (1) "water; wet").
Also sometimes in 17c. in a more positive sense, "abounding to excess or fullness, exuberant, plentiful," e.g. in "Paradise Lost," though what he meant by it here is anyone's guess:
With burnished neck of verdant gold, erect
Amidst his circling spires that on the grass
Of persons, in employment situations by 1928, chiefly British. Related: Redundantly. As a verb, redund has been tried at least once (1904); the etymological corresponding verb is the Frenchified redound.
1896, "aggressive, exuberant, touchy," American English, with -y (2) + feist "small dog," earlier fice, fist (American English, 1805); short for fysting curre "stinking cur," attested from 1520s, with present participle of now-obsolete Middle English fysten, fisten "break wind" (mid-15c.), from Proto-Germanic *fistiz "a fart," said to be from PIE *pezd- (see fart), but there are difficulties.
The 1811 slang dictionary defines fice as "a small windy escape backwards, more obvious to the nose than ears; frequently by old ladies charged on their lap-dogs." Compare also Danish fise "to blow, to fart," and obsolete English aske-fise, "fire-tender," literally "ash-blower" (early 15c.), from an unrecorded Norse source, used in Middle English for a kind of bellows, but originally "a term of reproach among northern nations for an unwarlike fellow who stayed at home in the chimney corner" [OED].