1. Either referring to muscle, a muscular man, or the
act of building muscle.
2. A word referring to a vaginal fart. Otherwise known as a "
queef".
"Tracy, whatchu doin',
girl?"
"Building some mousa."
"
Jenny, what was that noise?!"
"OMG, so
fucking sorry. I just had to mousa."
"Oh, I always have to after sex, it's alright. Let your mousa out, bb."