First member to hold a racket (7)
I believe the answer is:
leading
'first' is the definition.
(thesaurus)
'member to hold a racket' is the wordplay.
'member' becomes 'leg' (I've seen this before).
'to hold' indicates putting letters inside.
'racket' becomes 'din' (I've seen this before).
'a'+'din'='adin'
'leg' enclosing 'adin' is 'LEADING'.
(Other definitions for leading that I've seen before include "In first place; space between lines of print" , "'Showing the way, out in front (7)'" , "Prominent" , "Guiding by going in front" , "Most important; ahead" .)