I go early to bed, and I would advise you too to go 'by-by,' as they say aux enfants.
"by-by, don't break any records," Rupert called after the chauffeur.
Little baby Helen, who could only smile and wave “by-by” with one fat hand, piped in with her tiny voice, “Here I is!”
Every time I'd get a good grip on a job, long would come that convict-hunch, and I'd have to make my by-by.
by-by, Effie; you'll hear from me, perhaps, in the course of the week.
by-by until to-night—I'll drop down to the club and hear the latest from the front.
"by-by, poppy," said Chiffield, with a flippant wave of the hand.
by-by, called Sam; when you get that money call on me again and Ill take charge of it.
You want to do it all yourself—to fill the eye of the girl alone, and be tucked away to by-by for your pains—mais, quelle folie!
by-by, old boy, said Wallingford, as he turned into the street that led to his office.
Old English be- (unstressed) or bi (stressed) "near, in, by, during, about," from Proto-Germanic *bi "around, about" (cf. Old Saxon and Old Frisian bi "by near," Middle Dutch bie, Dutch bij, German bei "by, at, near," Gothic bi "about"), from *umbi (cognate with second element in PIE *ambhi "around," cf. Sanskrit abhi "toward, to," Greek amphi- "around, about;" see ambi-).
Originally an adverbial particle of place, in which sense it is retained in place names (Whitby, Grimsby, etc.). Elliptical use for "secondary course" (opposed to main; e.g. byway, also cf. by-blow "illegitimate child," 1590s) was in Old English. This also is the sense of the second by in the phrase by the by (1610s). By the way literally means "in passing by" (mid-14c.); used figuratively to introduce a tangential observation by 1540s.
Phrase by and by (early 14c.) originally meant "one by one," modern sense is from 1520s. By and large (1660s) originally was nautical, "sailing to the wind and off it," hence "in one direction then another."
in sporting use, a variant of by (prep). Originally in cricket, "a run scored on a ball that is missed by the wicket-keeper" (1746); later, in other sports, "position of one who is left without a competitor when the rest have drawn pairs" (1883), originally in lawn-tennis.
shortened form of good-bye. Reduplication bye-bye is recorded from 1709, though as a sound used to lull a child to sleep it is attested from 1630s.
in the expression "by myself" (A.V., 1 Cor. 4:4), means, as rendered in the Revised Version, "against myself."