The doctor had put too much water in the whisky (7)
I believe the answer is:
drowned
'too much water in the whisky' is the definition.
I can't judge whether this definition defines the answer.
'the doctor had' is the wordplay.
'the doctor' becomes 'Dr' (abbreviation).
'had' becomes 'owned' ('own' can be a synonym of 'have').
'dr'+'owned'='DROWNED'
'put' is the link.
Can you help me to learn more?
(Other definitions for drowned that I've seen before include "Submerged, flooded" , "Suffocated in water" , "Died underwater" , "Lost at sea" , "Died by submersion" .)