BYE-BYE

I. interjection

or by-by (ˈ)bī|bī

Etymology: baby-talk reduplication of goodbye

— used to express farewell

II. adverb

or by-by “

: out especially for a walk or ride — used with the verb go

if he wants to go bye-bye the baby may pat his head to indicate his desire for a hat — A.L.Gesell & Frances Ilg

III. noun

or by-by “

Etymology: reduplication of bye (II)

: bed , sleep

lie down … and go to bye-bye — Rudyard Kipling

IV. adverb

or by-by “

: to bed or sleep — used with the verb go

I'll run in and read for just a second … and then perhaps I'll go bye-bye — Sinclair Lewis