Inflexible belief of one who's dropped litter? (5)
I believe the answer is:
dogma
'inflexible belief' is the definition.
'dogma' can be an answer for 'belief' (dogma is a kind of belief). I am unsure of the 'inflexible' bit.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for dogma that I've seen before include "Inflexible principles" , "Doctrine laid down with authority" , "Doctrine accepted as true without proof" , "Blind faith required" , "Some believe it certainly" .)