Entering a sort of fruit (9)
I believe the answer is:
tangerine
'fruit' is the definition.
(I know that tangerine is a type of fruit)
'entering a sort' is the wordplay.
'sort' indicates anagramming the letters.
'entering'+'a'='enteringa'
'enteringa' with letters rearranged gives 'TANGERINE'.
'of' is the link.
(Other definitions for tangerine that I've seen before include "Taste" , "Small orange" , "fruit product" , "orange colour" , "Orange-type fruit" .)