Generally considered to be an insult used by the faint of heart. Can be heard in small scottish suburbs, but only the ones full of hoors and hoormasters. Also seems to be shouted out in rural pubs with barmaids who have been spitroasted by local farmers. It is also considered to be a small honour to be refered to as a mealer, usually after performing an act that is both incredibly dumb but also insanely funny.
Mealer1: totally threw a teacake off my dads head yesterday