Someone who doesn't give a fuck.
Niall Horan is the most carefreemofo in the world.
by Always Wrong October 07, 2012
Niall Horan from the biggest boy band, One Direction, is the biggest carefree mofo. He doesn't care. Niall Horan doesn't give a fuck.
Care free mofo doesn't need an example
by britishandirishboys June 18, 2013