The Collaborative International Dictionary of English v.0.48:

Unbusinesslike \Unbusinesslike\
   See businesslike.

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "unbusinesslike":
   amateurish, semiskilled, unaccomplished, uncoached, unendowed,
   unfinished, ungifted, uninitiated, unpolished, unprepared,
   unprimed, unprofessional, unschooled, unskilled, untalented,
   untaught, untrained, untutored