Assailants stare wildly, concealing cheap stuff (9)
I believe the answer is:
attackers
'assailants' is the definition.
('attacker' can be a synonym of 'assailant')
'stare wildly concealing cheap stuff' is the wordplay.
'wildly' indicates an anagram.
'concealing' is an insertion indicator.
'cheap stuff' becomes 'tack' (I can't explain this - if you can you should believe this answer much more).
'stare' anagrammed gives 'aters'.
'aters' enclosing 'tack' is 'ATTACKERS'.
Can you help me to learn more?
(Other definitions for attackers that I've seen before include "Those who assault" , "strikers?" , "They assail" , "Maybe muggers" , "They make aggressive attempts to score" .)