Fantastic Santa Claus regularly gives fruit (7)
I believe the answer is:
sultana
'fruit' is the definition.
(sultana is a kind of fruit)
'fantastic santa claus regularly' is the wordplay.
'fantastic' is an anagram indicator.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'claus' are 'lu'.
'santa'+'lu'='santalu'
'santalu' anagrammed gives 'SULTANA'.
'gives' is the link.
(Other definitions for sultana that I've seen before include "Grape; ruler's wife" , "Dried pale yellow seedless grape" , "pudding ingredient" , "Sovereign's mother perhaps" , "bit of a fruit cake" .)