bye-bye

[ interjection bahy-bahy; noun, adverb bahy-bahy ]
/ interjection ˈbaɪˈbaɪ; noun, adverb ˈbaɪˌbaɪ /

interjection

Informal. goodbye.

noun

Baby Talk. sleep.

Idioms

    go bye-bye, Baby Talk.
    1. to leave; depart; go out.
    2. to go to sleep; go to bed.

Origin of bye-bye

1700–10; apparently orig. nursery phrase used to lull a child to sleep, later construed as reduplicative form of bye, short for goodbye
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019