unprofessional
1. [ adjective ] not characteristic of or befitting a profession or one engaged in a profession
Examples:

"described in unprofessional language so that high school students could understand it" "was censured for unprofessional conduct" "unprofessional repairs"

Related terms: professional amateurish
Similar spelling:   unpromising
  unprotesting
  unprogressive
  unprofitably
  unprofitable