Miss announcement in departures leaving Britain for month (4)
I believe the answer is:
omit
'miss' is the definition.
(I know that miss can be written as omit)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for omit that I've seen before include "Disregard" , "Exclude - neglect" , "Drop" , "Fail to include" , "Leave out, do not include (4)" .)