It's included in an extra deal (5)
I believe the answer is:
trade
'it's included' is the definition.
I can't tell whether this defines the answer.
'in an extra deal' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TRADE' is hidden in the letters of 'extra deal'.
Can you help me to learn more?
(Other definitions for trade that I've seen before include "Commerce - traffic" , "Deal - occupation" , "Buy and sell, barter" , "Buy and sell in business" , "Commercial exchange of goods and services" .)