Thick blend of argon and tin (8)
I believe the answer is:
ignorant
'thick' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'blend of argon and tin' is the wordplay.
'blend of' indicates an anagram (I've seen this in other clues).
'and' is a charade indicator (letters next to each other).
'argon' put after 'tin' is 'tinargon'.
'tinargon' is an anagram of 'IGNORANT'.
Can you help me to learn more?
(Other definitions for ignorant that I've seen before include "not read" , "ill-advised" , "Ill-mannered" , "Illiterate - unaware" , "Lacking in education" .)