Run through really strange moral story (8)
I believe the answer is:
allegory
'moral story' is the definition.
(I've seen this before)
'run through really strange' is the wordplay.
'run' becomes 'go' (both can mean to function or work).
'through' is an insertion indicator (inserted letters go through the word).
'strange' indicates an anagram.
'really' anagrammed gives 'allery'.
'go' inserted inside 'allery' is 'ALLEGORY'.
(Other definitions for allegory that I've seen before include "literary device" , "Animal Farm, for example" , "Symbolic work" , "Symbolic tale - early log (anag)" , "Really go for this symbolic story" .)