No huge assortment is sufficient (6)
I believe the answer is:
enough
'sufficient' is the definition.
(similar in meaning)
'no huge assortment' is the wordplay.
'assortment' is an anagram indicator.
'no'+'huge'='nohuge'
'nohuge' anagrammed gives 'ENOUGH'.
'is' acts as a link.
(Other definitions for enough that I've seen before include "This is going no further!" , "Plenty" , "Adequate, sufficient" , "Ample, sufficient" , "satisfying" .)