Means the wine's last to go in (8)
I believe the answer is:
portends
'means' is the definition.
The answer and definition can be both to do with communicating as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?
'the wine's last to go in' is the wordplay.
'the wine's' becomes 'ports' (port is a kind of wine).
'last' becomes 'end' (I've seen this in another clue).
'to go in' indicates putting letters inside.
'ports' placed around 'end' is 'PORTENDS'.
Can you help me to learn more?
(Other definitions for portends that I've seen before include "Signals" , "Gives warning" , "Warns" , "Indicates by signs" , "Augurs, bodes" .)