Don urged criminal to crush society's outsiders (9)
I believe the answer is:
underdogs
'outsiders' is the definition.
The answer and definition can be both people as well as being plural nouns.
Maybe they are linked in a way I don't understand?
'don urged criminal to crush society's' is the wordplay.
'criminal' indicates anagramming the letters.
'to crush' is a charade indicator (letters next to each other) (in a down clue, some letters go on top of others).
'society' becomes 's' (common abbreviation in names of organisations).
'don'+'urged'='donurged'
'donurged' is an anagram of 'underdog'.
'underdog'+'s'='UNDERDOGS'
Can you help me to learn more?
(Other definitions for underdogs that I've seen before include "No drudges among those in subordinate positions" , "unfavoured ones" , "People expected to lose" .)