Take action on some issue (3)
I believe the answer is:
sue
'take action' is the definition.
(I've seen this in other clues)
'some issue' is the wordplay.
'SUE' is hidden within the letters.
But, I'm uncertain how the hidden word is indicated.
'on' is the link.
Can you help me to learn more?
(Other definitions for sue that I've seen before include "Bring a legal action" , "Susan (dim.)" , "Take legal action against (someone), girl's name" , "Begin legal proceedings against" , "Start proceedings against (someone)" .)