Sit or lounge around with a doctor (11)
I believe the answer is:
neurologist
'doctor' is the definition.
(I know that neurologist is a type of medical specialist)
'sit or lounge around' is the wordplay.
'around' is an anagram indicator.
'sit'+'or'+'lounge'='sitorlounge'
'sitorlounge' is an anagram of 'NEUROLOGIST'.
'with a' is the link.
(Other definitions for neurologist that I've seen before include "Medical specialist in the nervous system" , "Ignores lout (anag) - doctor specialising in the nervous system" , "Expert on the nervous system" .)