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 understand 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 explanation may well be incorrect...
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" .)