A hackneyed uncouth terminology used generally by the social public (sometimes cruelly) to brand anyone who's behavior or ideas is agreed to fall out the norm, if not merely coming across as unpleasant. Originally used against those considered sexually deviant of any sort, the term has evolved to be used for any type of personality that simply evokes disgust.
On the other hand, one can consider it a bit fruitless, considering the fact that social ideas and norms different vastly from geographical region to geographical region and consistently changes throughout history.
"OMG, those idiots next door support and probably practice polyamory. Also, one time when we were conversing, they brought up the concept of marrying one's sibling. They're such perverts!!"