Mammoth Uncensored Word List:
44 words ending with sh, 11 letters long

antitarnish bitterbrush bottlebrush buffalofish cavalierish distinguish dolphinfish floorpolish gangsterish hooliganish horseradish interparish lukewarmish martinetish milksoppish nightmarish novelettish overfurnish overnourish overslavish pantomimish pedagoguish photofinish pollyannish porcupinish preadmonish rabbitbrush reestablish soubrettish spatterdash spinsterish staggerbush standoffish steeplebush straightish surgeonfish synchromesh textbookish triggerfish trumpetfish vagabondish waterthrush werewolfish wishtonwish