Saint with halo, possibly part of racket (6)
I believe the answer is:
string
'part of racket' is the definition.
(I know that racquet head is the is part of of string.)
'saint with halo' is the wordplay.
'saint' becomes 'st' (abbreviation).
'with' means one lot of letters go next to another.
'halo' becomes 'ring' (synonyms).
'st'+'ring'='STRING'
'possibly' is the link.
(Other definitions for string that I've seen before include "This vest is made of large mesh" , "How long could a piece of it be?" , "Number of racehorses" , "Thread; sequence" , "Length of narrow cord" .)