Feature of some debit cards (4)
I believe the answer is:
chip
'feature of some debit cards' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for chip that I've seen before include "Slice - approach shot in golf" , "Sliver of wood or piece of potato" , "Thin piece, of wood or potato say" , "Roulette counter" , "loft" .)