Make, supply or apply plaster (6)
I believe the answer is:
render
I believe this is a quadruple definition!!
'make' is the first definition.
(rendering is a kind of making)
'supply' is the second definition.
(synonyms)
'or' acts as a link.
'apply' is the third definition.
The answer and definition can be both to do with communicating as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'plaster' is the fourth definition.
Can you help me to learn more?
(Other definitions for render that I've seen before include "Cause to be" , "Substance applied to masonry walls" , "Melt fat or perform song" , "Hand over; plaster" , "Depict artistically" .)