It can be taken in a bank (4)
I believe the answer is:
reef
'a bank' is the definition.
(I've seen this before)
'it can be taken in' is the wordplay.
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'can' becomes 'ref' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'be taken in' indicates putting letters inside (some letters have taken in others).
'e' placed inside 'ref' is 'REEF'.
Can you help me to learn more?
(Other definitions for reef that I've seen before include "Marine formation" , "Chain of rocks underwater" , "Bank of jagged rock near the surface of the sea" , "key" , "Coral structure" .)