Amateurish \Am`a*teur"ish\, a. In the style of an amateur; superficial or defective like the work of an amateur. -- {Am`a*teur"ish*ly}, adv. -- {Am`a*teur"ish*ness}, n. [1913 Webster]
amateurishness \amateurishness\ n. Behavior that demonstrates a lack of professional competency. [WordNet 1.5]