A catch phrase used predominantly in the southern Appalachians that can mean nearly anything but most commonly routine expressions which are easily interpreted like 'hello', 'yes' or 'thank you'. Context,
intonation & non-verbal cues are often the key to
interpreting actual meaning.
Roommate:
Welcome home dude.
Other Roommate:
Mow mow ('hey, it's been a long day and I'm too tired to use real words')
Person 1: Can you
pass the gravy?
Person 2: Sure, here you go.
Person 1: Mow mow. Mmmm...
mow mow! (Thank you... mmmm... hey that's good gravy!)