Minor offence (12)
'minor offence' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for misdemeanour that I've seen before include "Minor offence" , "Minor violation" , "Minor wrongdoing" .)
I believe this is a double definition.
'minor' is the first definition.
(I've seen this before)
'offence' is the second definition.
(I know that slight is a type of rebuff)
(Other definitions for slight that I've seen before include "Insignificant, flimsy" , "Small in extent" , "of no great significance" , "Minor - affront" , "Disregard - snub" .)