Definition of "amateurish"

amateurish

/ˈæ.mə.t͡ʃʊɚ.ɪʃ/

adjective
comparative more amateurish, superlative most amateurish
1. (derogatory) Suggesting or reflecting the efforts of an amateur; not seeming professional or polished.
  Quotations
  Some of the photographs are new and interesting, but many captions are amateurish, uninformative or simply careless.
  1964 September, “New Books: The History of Railways. By Erwin Berghaus. Barrie & Rockcliff. 35s.”, in Modern Railways, page 222