From Middle English burblen (to bubble).
burble (plural burbles)
- A bubbling, gurgling sound, as of a creek.
- A gush of rapid speech.
- The turbulent boundary layer about a moving streamlined body.
- To bubble; to gurgle.
- To babble; to speak in an excited rush.
- She burbled on, as if I cared to listen.
to bubble, to gurgle
- (etymology) American Heritage Dictionary.