Ensure you're heard (4)
I believe the answer is:
yell
'ensure you're heard' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yell that I've seen before include "Clement --, politician" , "Shout - Shetland island" , "Utter a sudden loud cry" , "Bawl, yowl" , "Scream" .)