Leave post (3,3)
I believe the answer is:
get off
This could be a double definition.
'leave' is the first definition.
(getting off is a kind of leaving)
'post' is the second definition.
The answer and definition can be both to do with communicating as well as being verbs in their base form.
Perhaps there's a link between them I don't understand?
Can you help me to learn more?
(Other definitions for get off that I've seen before include "Leave train or dismount" , "Be acquitted - go to sleep" , "Escape all punishment" , "Not be punished" , "shed" .)