bush league

Short definition from Wiktionary

Noun

1. 1
   A professional sports association at the lower levels of minor league organization.
2. 2
   A low-ranking or inferior level among groups, professions, organizations, etc.

Adjective

1. 1
   Of inferior quality.
2. 2
   Amateurish, unprofessional, unpolished, juvenile.
3. 3
   Minor-league; second-rate.