Pro armed and yelling leads raid (5)
I believe the answer is:
foray
'raid' is the definition.
(I know that raid can be written as foray)
'pro armed and yelling leads' is the wordplay.
'pro' becomes 'for' (I've seen this before).
'armed' becomes 'a' (this could be a standard abbreviation I've not previously seen).
'and' means one lot of letters go next to another.
'leads' says to take the initial letters.
The initial letter of 'yelling' is 'y'.
'for'+'a'+'y'='FORAY'
Can you help me to learn more?
(Other definitions for foray that I've seen before include "Raid into enemy territory" , "Brief attack" , ".A sudden attack or raid" , "Depredation" , "Raid or incursion" .)