Like rebellious young men of yester year? (5)
I believe the answer is:
angry
'like' is the definition.
Both the definition and answer are adjectives. Maybe you can see a link between them that I don't see?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for angry that I've seen before include "Irate, mad" , "Vexed" , "Upset" , "Furious" , "Inflamed" .)