The ones starting trouble with a cry (4)
I believe the answer is:
they
'the ones' is the definition.
Both the definition and answer are plural nouns.
Perhaps you can see an association between them that I don't see?
'starting trouble with a cry' is the wordplay.
'starting' says to take the initial letters.
'with' means one lot of letters go next to another.
'a cry' becomes 'hey' (I can't justify this - if you can you should believe this answer much more).
The first letter of 'trouble' is 't'.
't'+'hey'='THEY'
Can you help me to learn more?
(Other definitions for they that I've seen before include "Do -- Know It's Christmas (Band Aid)" , "Third person plural" , "Pronoun for more than one" , "Those people (vb. subject)" , "People generally" .)