Common colloquialism in rural western United States. Means "mhmm, bye" "um, bye" "ok, bye," "goodbye" or simply "bye." The "M" sound is used as a space filler and there is no pause between The "M" and "bye" sounds. Normally used as a polite, informal way to end a phone conversation, but is occassionally used in-person, as well.
Caller "How late are you open today?"
Receptionist "We're open until six."
Caller "Okay, Thank you."
Receptionist "You're welcome, m-bye."
Caller "Bye!"
Receptionist "We're open until six."
Caller "Okay, Thank you."
Receptionist "You're welcome, m-bye."
Caller "Bye!"
by bonnylea May 10, 2010