Woos Ms Williams and Mr O'Connor (9)
I believe the answer is:
serenades
'woos' is the definition.
(both can mean to court romantically)
'ms williams and mr o'connor' is the wordplay.
'ms williams' becomes 'serena' (tennis player Serena Williams).
'and' means one lot of letters go next to another.
'mr o'connor' becomes 'des' (entertainer Des O'Connor).
'serena'+'des'='SERENADES'
(Other definitions for serenades that I've seen before include "Woos with music" , "airs" , "Pieces of music" , "Love songs under fair lady's window" .)