### Clue: Aristocrat ultimately insignificant like an upper-class hearty? (6)
### Answer: TWEEDY 
 ### Explanation: Definition: like an upper-class hearty
 **The last letter of**(.. ultimately) "Aristocrat" + WEEDY(insignificant;thin and weak in appearance).
Defn: Describing one who is fond of the hearty and robust outdoor life, as personified by the upper-class country gentry in tweeds.