Heartless upstart right to cut gas for which there's no charge (7)
I believe the answer is:
neutron
'no charge' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'heartless upstart right to cut gas for which there's' is the wordplay.
I cannot quite see how this works, but
'upstart' could be 'u' (start of the word 'up') and 'u' is found within the answer.
'right' could be 'r' (common abbreviation) and 'r' is present in the answer.
'to' is present in the answer.
'gas' could be 'n' (chemical symbol for nitrogen) and 'n' is located in the answer.
'there's' could be 'n' (I've seen this in other clues) and 'n' is present in the answer.
A single letter 'e' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for neutron that I've seen before include "one isn't charged" , "Charged particle" , "tiny amount" , "Turn one (anag) - kind of bomb" , "Subatomic particle with no electric charge" .)