Explosive cavalry assault (6)
I believe the answer is:
charge
This could be a double definition.
'explosive' is the first definition.
(I know that charge is a type of explosive)
'cavalry assault' is the second definition.
'charge' can be an answer for 'assault' (thesaurus). I am unsure of the 'cavalry' bit.
Can you help me to learn more?
(Other definitions for charge that I've seen before include "Fee; accuse" , "Move quickly and violently" , "Demand in payment" , "Amount to pay - attack" , "Make a rush at" .)