Touch and go (4)
I believe the answer is:
move
This clue is a double definition.
'touch' is the first definition.
(I know that touch is a more specific form of communicate)
'go' is the second definition.
(I know that go is a more specific form of exit)
'and' acts as a link.
(Other definitions for move that I've seen before include "Go; change opinion" , "Budge" , "Change address" , "Change residence; propose formally" , "Shift" .)