1.SSPOORsomeone who has nowhere to live, and sleeps in the street or in cheap hostels 居无定所的人，露宿街头者；住廉价客栈的人
2.someone who is very lazy 懒人
Examples from the Corpus
dosser• You don't normally find dossers in the countryside.• I had just turned sixteen and they put me in this place that was really for dossers.• Male speaker we're not dossers on the street, we're ordinary people.• What I did with the dossers is put them in very strange settings.