Identity of second Santa helper (4)
I believe the answer is:
self
'identity' is the definition.
(I've seen this before)
'second santa helper' is the wordplay.
'second' becomes 's' (common abbreviation**).
'santa helper' becomes 'elf' (I've seen this before).
's'+'elf'='SELF'
'of' acts as a link.
(Other definitions for self that I've seen before include "Personality" , "Ego, identity" , "A person's awareness of their own identity" , "Will the author" , "Will perhaps" .)