Is it farther or further?
"make a bubbling sound," c.1300, imitative. Related: Burbled; burbling.
[Lewis Carroll's "Jabberwocky"] Like flame, but connotes that the source is truly clueless and ineffectual (mere flamers can be competent). A term of deep contempt. "There's some guy on the phone burbling about how he got a DISK FULL error and it's all our comm software's fault." This is mainstream slang in some parts of England.