in a way that does not show the standard of behaviour that is expected from someone doing a particular job

She's acting unprofessionally, so you need to tackle this problem as soon as possible. 她表现得非常不专业，所以你需要尽快解决这个问题。

The social worker behaved unprofessionally and was disrespectful. 这名社会工作者的行为不专业，不尊重人。