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' says to put letters next to each other.
'end of' suggests 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" .)