Can be let off for hissing at the players! (5)
I believe the answer is:
steam
'can be let' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'for hissing at the players' is the wordplay.
'for hissing' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'at' is a charade indicator (letters next to each other).
'the players' becomes 'team' (sports team).
's'+'team'='STEAM'
'off' is the link.
Can you help me to learn more?
(Other definitions for steam that I've seen before include "Old-fashioned power" , "It's water mist, mates" , "comes with a hiss?" , "Gas formed by vaporizing water at 100?C" , "Hot water vapour" .)