Extinguish national spirit (6)
I believe the answer is:
scotch
'spirit' is the definition.
(I've seen this before)
'extinguish national' is the wordplay.
I cannot quite see how this works, but
'national' could be 'scot' (someone from Scotland) and 'scot' is present in the answer.
The remaining letters 'ch' is a valid word 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 scotch that I've seen before include "A drink; crush" , "Prevent -- frustrate" , "Put the lid on" , "Finish off" , "Decisively put an end to" .)