One reason to be masked (3)
I believe the answer is:
gas
'one reason' is the definition.
The definition and answer 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?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for gas that I've seen before include "Wind" , "American fuel" , "Petrol (US)" , "eg Helium" , "Neon, for example" .)