Santa sits around, requiring a helper (9)
I believe the answer is:
assistant
'a helper' is the definition.
(I know that helper can be written as assistant)
'santa sits around' is the wordplay.
'around' indicates anagramming the letters.
'santa'+'sits'='santasits'
'santasits' is an anagram of 'ASSISTANT'.
'requiring' acts as a link.
(Other definitions for assistant that I've seen before include "Attendant, helper" , "second" , "One helping" , "one helps out" , "Deputy, subordinate" .)