Police came to rally (3)
I believe the answer is:
met
'police' is the definition.
(London Metropolitan Police)
'came to rally' is the wordplay.
'MET' is hidden in amongst the letters.
But, I am uncertain how this is indicated.
Can you help me to learn more?
(Other definitions for met that I've seen before include "Came across - police in London" , "Encountered or touched" , "Encountered pro tem" , "Opera company" , "Came together, encountered" .)