Turn one's nose up at garbage (6)
I believe the answer is:
refuse
This might be a double definition.
'turn one's nose' is the first definition.
'refuse' can be an answer for 'turn' (thesaurus). I'm not certain of the 'one's nose' bit.
'up at garbage' is the second definition.
'refuse' can be an answer for 'garbage' ('refuse' can be a synonym of 'garbage'). I'm unsure of the 'up at' bit.
Can you help me to learn more?
(Other definitions for refuse that I've seen before include "Decline, repudiate" , "Decline to jump (a fence)" , "Deny; rubbish" , "Waste, garbage" , "Turn down, reject" .)