Thirsty doctor coming to end of surgery (3)
I believe the answer is:
dry
'thirsty' is the definition.
(similar in meaning)
'doctor coming to end of surgery' is the wordplay.
'doctor' becomes 'dr' (abbreviation).
'coming to' means one lot of letters go next to another.
'end of' indicates one should take the final letters.
The final letter of 'surgery' is 'y'.
'dr'+'y'='DRY'
(Other definitions for dry that I've seen before include "Arid as some wine may be" , "Dehydrated" , "Arid; teetotal" , "Desiccated" , "Remove moisture" .)