Karate grade (3)
(Other definitions for dan that I've seen before include "Judo level and Wicklow lake" , "book (abbreviated version)" , "Grade level in judo" , "Black-belt grade of proficiency" , "-- Dare, comic hero" .)
(Other definitions for don that I've seen before include "Nod off like Mafia chief" , "Mafia supremo" , "A Mafia chief like Corleone" , "Mafia boss" , "Put on for the Mafia chief and Spanish aristocrat" .)