Carol released form of butane (5)
I believe the answer is:
calor
'form of butane' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'carol released' is the wordplay.
'released' indicates anagramming the letters (letters released from their original order).
'carol' is an anagram of 'CALOR'.
Can you help me to learn more?
(Other definitions for calor that I've seen before include "This gas is stored in containers for domestic use" , "Gas stored in containers for domestic heating" , "liquid gas" , "Cooking gas" , "Commercial gas in a container for domestic use" .)