the sound you make if you open ur mouth while making the m sound
(perhaps that is why people say um because they are opening and then closeing their mouths)
your responce "uhhhhhhhhhhh wha??"
*Used for "a" in a certain sentance
*One of many ways a woman moans when receive sexual satisfaction.
"Uh pea-sized town with limabean-sized dreams."
"Uh....uhhh.....oh yes! Uh! Uuuh!! Uhhh....UH!"