Check weapon for magnetism (5)
I believe the answer is:
charm
'magnetism' is the definition.
(thesaurus)
'check weapon' is the wordplay.
'check' becomes 'ch' (I've seen this in other clues).
'weapon' becomes 'arm' (I've seen this before).
'ch'+'arm'='CHARM'
'for' acts as a link.
(Other definitions for charm that I've seen before include "a delightful feature" , "Delightfulness" , "Entrance, bewitch" , "pleasing feature" , "Make delighted" .)