An example of an unprofessional letter is when a CEO of a company gets mad and sends a letter to a customer calling him an offensive slang word.
- violating the rules or ethical code of a given profession
- not of, characteristic of, belonging to, or connected with a profession; nonprofessional
- a. Not in a profession.b. Not a qualified member of a professional group.
- Not conforming to the standards of a profession: unprofessional behavior.
- Characteristic of an amateur; inexpert.
(comparative more unprofessional, superlative most unprofessional)
un- +"Ž professional