"garrulous, talkative," 1719, originally Scottish, from gab (n.) + -y (2). Related: Gabbiness.
Entries linking to gabby
gab n.
"action of talking," earlier "chatter, loquacity, idle talk" (mid-13c.), also "falsehood, deceit," originally "a gibe, a taunt" (c. 1200), mid-13c., probably from a Scandinavian source akin to Old Norse gabb "mocking, mockery," and in part from Old French gap, gab "joke, jest; bragging talk," which also is probably from Scandinavian (compare gab (v.)). Probably also there is influence from Scottish and northern English gab "the mouth" (see gob (n.2)); OED reports the word "Not in dignified use." Gift of (the) gab "talent for speaking" is from 1680s.
-y 2
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.