Naughty mates possibly let off (5)
I believe the answer is:
steam
'let off' is the definition.
Although both the answer and definition are verbs in their base form, I don't understand how they can define each other.
'naughty mates' is the wordplay.
'naughty' indicates an anagram.
'mates' is an anagram of 'STEAM'.
'possibly' is the link.
Can you help me to learn more?
(Other definitions for steam that I've seen before include "Kettle emission" , "Gas formed by vaporizing water at 100?C" , "Water-vapour" , "Driving force" , "Mates (anag)" .)