mid-15c., from leak (n.) + -y (2). Related: Leakiness. Slang sense of "unable to keep a secret" attested from 1704.
Entries linking to leaky
leak n.
"hole by which liquid enters or escapes," late 15c., from leak (v.) or Old Norse cognate leka. Sense of "revelation of secret information" is from 1950. Meaning "act of urination" is attested from 1934 ("Tropic of Cancer"); but the verb meaning "to piss" is from 1590s: "Why, you will allow vs ne're a Iourden [i.e. a chamberpot], and then we leake in your Chimney." ["I Hen. IV," II.i.22]
-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.