Loud weapon standard, by the sound of it? (6)
I believe the answer is:
cannon
'loud weapon' is the definition.
'cannon' can be an answer for 'weapon' (cannon is a kind of weapon). I'm unsure of the 'loud' bit.
'standard by the sound of it?' is the wordplay.
'standard' becomes 'canon' (I've seen this before).
'by the sound of it?' shows a homophone (sound like).
'canon' sounds like 'CANNON'.
Can you help me to learn more?
(Other definitions for cannon that I've seen before include "Item of heavy artillery" , "The large gun sounds like a church dignitary" , "Heavy ordnance" , "Snooker shot" , "Weapon firing large balls" .)