Girls getting upset with men — they’re such troublemakers! (8)
I believe the answer is:
gremlins
'such troublemakers' is the definition.
The answer and definition can be both people as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'girls getting upset with men' is the wordplay.
'getting upset with' indicates anagramming the letters.
'girls' anagrammed with 'men' can make 'GREMLINS'.
'they're' acts as a link.
Can you help me to learn more?
(Other definitions for gremlins that I've seen before include "Mischievous sprites, maybe in machinery" , "Mischievous sprites responsible for mechanical problems" .)