outsider
noun [ C ]
uk/ˌaʊtˈsaɪdər/ us WORKPLACE
someone who is paid by a company or organization to do a particular job, but who is not a permanent employee:
In 2009, the company hired an outsider with marketing experience in an effort to revive its business.
someone who is not directly involved in a situation:
To outsiders, it looked as if the company was doing well.