pos ‧ er /ˈpəʊzə $ ˈpoʊzər/ BrE AmE noun [countable] informal
[ Date: 1800-1900 ; Language: French ; Origin: poser ; ⇨ ↑ pose 1 ]
1 . British English ( also po‧seur /pəʊˈzɜː $ poʊˈzɜːr/) someone who pretends to have a quality or social position they do not really have, usually in order to make people notice or admire them:
You meet a lot of posers in this job.
2 . a difficult question:
That’s a real poser.