incompetent

Synonyms: amateur amateurish awkward bungling bush-league clumsy disqualified floundering helpless inadequate incapable ineffectual inefficient ineligible inept inexperienced inexpert insufficient maladroit not cut out for not equal to not have it out to lunch raw unadapted unequipped unfit unfitted unhandy uninitiated unproficient unqualified unskilled untrained useless

Antonyms: able adept capable competent dexterous effective efficient experienced expert proficient skillful