League's leader won, it's understood (7)
I believe the answer is:
learned
'understood' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?
'league's leader won' is the wordplay.
'leader' says to take the initial letters.
'won' becomes 'earned' (I've seen this in another clue).
The initial letter of 'leagues' is 'l'.
'l'+'earned'='LEARNED'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for learned that I've seen before include "Found out; educated" , "Erudite, knowledgeable" , "widely read" , "Knowledgeable - scholarly" , "Absorbed information about Leander" .)