Knock down leader of legion roughly on march (8)
I believe the answer is:
demolish
'knock down' is the definition.
(I've seen this before)
'leader of legion roughly on march' is the wordplay.
'leader of' indicates taking the first letters.
'roughly' becomes 'ish' (I can't explain this - if you can you should give a lot more credence to this answer).
'on' says to put letters next to each other.
'march' becomes 'demo' (as in a demonstration).
The first letter of 'legion' is 'l'.
'l'+'ish'='lish'
'lish' put after 'demo' is 'DEMOLISH'.
Can you help me to learn more?
(Other definitions for demolish that I've seen before include "Knock down, say a building" , "Break down" , "Destroy completely" , "Pull or tear down" , "Knock or tear down" .)