Give cards for snap? (3,4,2)
I believe the answer is:
get shot of
'give cards' is the definition.
(both can mean to dismiss someone)
'snap?' is the wordplay.
I cannot really understand how this works, but
'snap?' could be 'shot' (I've seen this before) and 'shot' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'for' acts as a link.
(Other definitions for get shot of that I've seen before include "ditch?" , "Kick" , "Manage to photograph" , "Eliminate" .)