Took in one doctor in initial plot (7)
I believe the answer is:
imbibed
'took in' is the definition.
('imbibe' can be a synonym of 'take in')
'one doctor in initial plot' is the wordplay.
'one' becomes 'i' (Roman numeral).
'doctor' becomes 'mb' (abbreviation for Bachelor of Medicine).
'initial' indicates taking the first letters.
'plot' becomes 'bed' (a plot of land).
The first letter of 'in' is 'i'.
'i'+'mb'+'i'+'bed'='IMBIBED'
(Other definitions for imbibed that I've seen before include "Drank (alcohol)" , "Drunk" .)