Ruling family in a bad way, going to supermarket (8)
I believe the answer is:
grimaldi
'ruling family' is the definition.
'grimaldi' can be an answer for 'family' (I have seen 'Genoese family' mean 'grimaldi' so perhaps 'family' could also mean 'grimaldi'). I am unsure of the 'ruling' bit.
'in a bad way going to supermarket' is the wordplay.
'in a bad way' becomes 'grim' (I can't explain this - if you can you should give a lot more credence to this answer).
'going to' says to put letters next to each other.
'supermarket' becomes 'Aldi' (Aldi is a supermarket chain).
'grim'+'aldi'='GRIMALDI'
Can you help me to learn more?
(Other definitions for grimaldi that I've seen before include "English clown's" , "Ruling house of Monaco" , "Pantomime actor" , "Joseph -, eighteenth to nineteenth century English clown" , "Genoese family" .)