Not meeting the standards of skill, conduct, or behavior expected in a professional setting.
From the prefix 'un-' (not) + 'professional' from Latin 'professio' (declaration, occupation). The word only became common in the late 19th century as modern professional standards developed.
What counts as 'unprofessional' changes wildly across industries and cultures—showing emotion might be unprofessional in law but essential in therapy, and saying 'no' might be unprofessional in some workplaces but healthy in others. It's actually a really good word for exposing invisible workplace rules.
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