Lightning power in Blitz (5)
I believe the answer is:
rapid
'lightning' is the definition.
(both can mean very fast)
'power in blitz' is the wordplay.
'power' becomes 'p' (symbol in physics).
'in' means one lot of letters goes inside another.
'blitz' becomes 'raid' (I can't justify this - if you can you should give a lot more credence to this answer).
'p' put inside 'raid' is 'RAPID'.
Can you help me to learn more?
(Other definitions for rapid that I've seen before include "Showing pace" , "Moving at speed" , "moving fast" , "Swift, speedy" , "Flying" .)