Identity of Santa's top little helper (4)
I believe the answer is:
self
'identity' is the definition.
(I've seen this before)
'santa's top little helper' is the wordplay.
'top' says to take the initial letters.
'little helper' becomes 'elf' (I can't justify this - if you can you should give a lot more credence to this answer).
The first letter of 'santa' is 's'.
's'+'elf'='SELF'
'of' is the link.
Can you help me to learn more?
(Other definitions for self that I've seen before include "A person's awareness of their own identity" , "Will perhaps" , "One's individuality" , "Will the writer?" , "Personality" .)