Inebriated tennis legend admitted by second doctor (7)
I believe the answer is:
smashed
'inebriated' is the definition.
(thesaurus)
'tennis legend admitted by second doctor' is the wordplay.
'tennis legend' becomes 'ashe' (I've seen this in another clue).
'admitted by' is an insertion indicator.
'second' becomes 's' (common abbreviation).
'doctor' becomes 'md' (synonyms).
's'+'md'='smd'
'ashe' inserted inside 'smd' is 'SMASHED'.
(Other definitions for smashed that I've seen before include "Broke into sharp pieces" , "Broken in pieces" , "Affected by drug" , "Broke into small pieces" , "Drunk (as a broken bottle?)" .)