Went in hospital ward before introduction to doctor (7)
I believe the answer is:
entered
'went in' is the definition.
('enter' can be a synonym of 'go in')
'hospital ward before introduction to doctor' is the wordplay.
'hospital ward' becomes 'ENT' (Ear, Nose and Throat department).
'before' becomes 'ere' (poetic term for 'before').
'introduction to' says to take the initial letters.
The first letter of 'doctor' is 'd'.
'ent'+'ere'+'d'='ENTERED'
(Other definitions for entered that I've seen before include "Went in and registered as competitor" , "Logged; arrived" , "moved in" , "Enrolled or went in" , "Came in; recorded" .)