It can break rising young men (7)
I believe the answer is:
scandal
'it' is the definition.
The definition suggests a singular noun which matches the answer.
'can break rising young men' is the wordplay.
'break' indicates putting letters inside (inserted letters break into the word).
'rising' says the letters should be written backwards (in a down clue, letters go up).
'young men' becomes 'lads' (I've seen this in another clue).
'lads' back-to-front is 'sdal'.
'can' put into 'sdal' is 'SCANDAL'.
Can you help me to learn more?
(Other definitions for scandal that I've seen before include "Cause of general outrage" , "It injures reputation" , "something injurious to one's reputation" , "Subject of Sheridan's school" , "disgraceful behaviour" .)