exuberant: [15] Exuberant comes via French from the present participle of Latin exūberāre ‘be abundant’. This was a compound verb formed from the intensive prefix ex- and ūberāre ‘be productive’, a derivative of ūber ‘fertile’. This in turn was an adjectival use of the noun ūber ‘udder’, which came from the same ultimate source (Indo-European *ūdhr-) as English udder. => udder
exuberant (adj.)
mid-15c., from Middle French exubérant and directly from Latin exuberantem (nominative exuberans) "overabundance," present participle of exuberare "be abundant, grow luxuriously," from ex- "thoroughly" (see ex-) + uberare "be fruitful," related to uber "udder," from PIE root *eue-dh-r- (see udder). Related: Exuberantly; exuberate; exuberating.