Cheat me out of a weapon (7)
I believe the answer is:
machete
'a weapon' is the definition.
(I know that machete is a type of knife)
'cheat me out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'cheat'+'me'='cheatme'
'cheatme' with letters rearranged gives 'MACHETE'.
'of' is the link.
(Other definitions for machete that I've seen before include "Heavy South American knife" , "Heavy knife used as weapon" , "Jungle blade" , "Large heavy knife for cutting vegetation" , "Knife for hacking" .)