Legal guideline in sport failing to protect group of stars (4,2,3)
I believe the answer is:
rule of law
'legal guideline' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'sport failing to protect group of stars' is the wordplay.
'sport' becomes 'RU' (rugby union).
'failing' becomes 'flaw' (I've seen this before).
'to protect' means one lot of letters goes inside another (inserted letters are protected or taken in).
'group of stars' becomes 'leo' (Leo is a constellation).
'ru'+'flaw'='ruflaw'
'ruflaw' enclosing 'leo' is 'RULE OF LAW'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for rule of law that I've seen before include "A court must" , "Nomocracy" , "Orderly consensus" , "order" .)