Write the report about anaesthetic (5)
I believe the answer is:
ether
'anaesthetic' is the definition.
(ether is a kind of anaesthetic)
'write the report about' is the wordplay.
'about' indicates a hidden word (the clue goes around or about the answer).
'ETHER' can be found hidden inside 'write the report'.
(Other definitions for ether that I've seen before include "Old anaesthetic -- three (anag)" , "Highly flammable liquid once used as an anaesthetic" , "I'm volatile" , "An early anaesthetic" , "There goes the anaesthetic" .)