Spy giving up date of birth (including name) (4)
I believe the answer is:
bond
'spy' is the definition.
(James Bond)
'up date of birth including name' is the wordplay.
'up' is a reversal indicator (in down clue: letters go upwards).
'date' becomes 'd' (common abbreviation eg in DOB, date of birth).
'of birth' becomes 'ob' (this could be a standard abbreviation of which I'm unaware).
'including' indicates putting letters inside.
'name' becomes 'n' (common abbreviation e.g. on forms).
'd'+'ob'='dob'
'dob' enclosing 'n' is 'dnob'.
'dnob' back-to-front is 'BOND'.
'giving' acts as a link.
Can you help me to learn more?
(Other definitions for bond that I've seen before include "Something that joins together, or a financial document" , "Tie - 007" , "Certificate of debt" , "secure?" , "Binding agreement; double zero seven" .)