No smart set -- jumbled collection of various items (10)
I believe the answer is:
assortment
'collection of various items' is the definition.
(an assortment of items)
'no smart set jumbled' is the wordplay.
'jumbled' indicates an anagram.
'no'+'smart'+'set'='nosmartset'
'nosmartset' anagrammed gives 'ASSORTMENT'.
(Other definitions for assortment that I've seen before include "Variety" , "Mixture" , "Miscellany" , "Miscellaneous collection" , "Medley" .)