amateurish vs bush league

amateurish

adj
  • Suggesting or reflecting the efforts of an amateur; not seeming professional or polished. 

bush league

adj
  • Amateurish, unprofessional, unpolished, juvenile. 

  • Of inferior quality. 

noun
  • A professional sports association at the lower levels of minor league organization. 

  • A low-ranking or inferior level among groups, professions, organizations, etc. 

How often have the words amateurish and bush league occurred in a corpus of books? (source: Google Ngram Viewer )