Coarsest

4 clues
Roughest
Least fine
Most grating
Least refined
Similar answers:
Apsestore
Asaparenthesestimable
Basest
Basestbasset
Basestealer
Basesthound
Buncoartist
Burmesestevens
Businessestablishment
Casesthejoint
Casestudies
Casestudy
Chaisestadium
Chasestudy
Cheesesteak
Closest
Coarse
Coarsecourse
Coarsegrained
Coarsegrainedwood