Steal old currency tucked inside thin coat (8)
I believe the answer is:
peculate
'steal old' is the definition.
'peculate' can be an answer for 'steal' (peculating is a kind of stealing). I'm unsure of the 'old' bit.
'currency tucked inside thin coat' is the wordplay.
I cannot quite see how this works, but
'currency' could be 'ecu' (I have seen 'European currency ' mean 'ecu' so perhaps 'currency' could also mean 'ecu') and 'ecu' is present in the answer.
'coat' could be 'plate' (plating is a kind of coating) and 'plate' is found in the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for peculate that I've seen before include "Embezzle money with cute plea" , "Appropriate" , "Steal money entrusted to one's care, embezzle" , "Embezzle money having pale, cute appearance" .)