Euros sold out as nothing to be sniffed at (9)
I believe the answer is:
odourless
'nothing to be sniffed at' is the definition.
I can't judge whether this defines the answer.
'euros sold out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'euros'+'sold'='eurossold'
'eurossold' anagrammed gives 'ODOURLESS'.
'as' is the link.
Can you help me to learn more?
(Other definitions for odourless that I've seen before include "devoid of smell" , "Without smell" , "having no hint of whiff" , "Without so much as a whiff" , "descriptive of clean air" .)