Colloquial description of a one piece leather suite used for motorcycle riding. Term originally coined by highly esteemed female Australian bike rider of Melbourne location many many years ago. Since purchasing her own "onesies" it has been decreeded under Melbourne Bike Rider assesment to be the hottest arse in a set of onesies evvaaaaaaaaaaar !!!
she " Dude onesies for the track today ?"
dude "hell yeah help me pull 'em on"
she " meh, your arse aint never gunna look as good as mine does in onesies"