Back at home with doctor - now everywhere (11)
I believe the answer is:
omnipresent
'everywhere' is the definition.
(I've seen this in another clue)
'back at home with doctor now' is the wordplay.
'back' says the letters should be written in reverse.
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'with' says to put letters next to each other.
'doctor' becomes 'mo' (medical officer).
'now' becomes 'present' (the present time).
'in'+'mo'='inmo'
'inmo' in reverse letter order is 'omni'.
'omni'+'present'='OMNIPRESENT'
(Other definitions for omnipresent that I've seen before include "Everywhere at the same time" , "Ubiquitous" , "Constantly encountered" , "travelling all over the place" , "(Of God) everywhere simultaneously" .)