Represent doctor on duty primarily in case of emergency (6)
I believe the answer is:
embody
'represent' is the definition.
(I know that embody is a type of represent)
'doctor on duty primarily in case of emergency' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus).
'primarily' says to take the initial letters.
'in' is an insertion indicator.
'case of' suggests removing the centre (outsides of).
'emergency' with its middle removed is 'ey'.
The first letters of 'on duty' is 'od'.
'mb'+'od'='mbod'
'mbod' going within 'ey' is 'EMBODY'.
(Other definitions for embody that I've seen before include "Express ideas in visible or tangible form" , "Contain within oneself, incorporate" , "Include (something) as a constituent part" , "Incorporate or express in visible form" , "Give form to (idea)" .)