1. Used as a term for giving props/shots to a particular item based on a scale of 1-5 stars.
2. Is interchangeable with the word heck, hell, fuck, fuckers or mutha fuckers in a sentence without fear of reducing the value or original intention of the speaker.
'OMG, this pizza is almost perfect...I give it 4 outta 5 mutha fuckstars.'
'What in the mutha fuckstars is up?'
'You mutha fuckstars best get to steppin bro.'
'Y'allz actin like a buncha mutha fuckstars, bogarting ain't nice.'