Flammable liquid used there (5)
I believe the answer is:
ether
'flammable liquid' is the definition.
(I've seen this in another clue)
'used there' is the wordplay.
'used' indicates an anagram.
'there' anagrammed gives 'ETHER'.
(Other definitions for ether that I've seen before include "Highly flammable liquid once used as an anaesthetic" , "Medium supposedly" , "The gas is there, oddly" , "Colourless volatile highly inflammable liquid" , "Formerly an anaesthetic" .)