unskillful

The wickedness and cruelty of the crime were only equalled by the clumsy and unskilful manner of its perpetration.

Perhaps he sensed her coming, heard her; or perhaps she was unskilful.

Though he designed and began it, he left it to some unskilful apprentices to finish.

Without being a great soldier, Frederick was not unskilful in warfare, but was better acquainted with the arts of diplomacy.