For the final, relative is no longer in relays (6,2)
I believe the answer is:
passes on
'no longer in relays' is the definition.
The answer and definition can be both to do with communicating as well as being verbs in their -s form.
Maybe there's an association between them I don't understand?
'for the final relative' is the wordplay.
'for' becomes 'pass' (I can't justify this - if you can you should believe this answer much more).
'final' suggests the final letters.
'relative' becomes 'son' (son is a kind of relative).
The final letter of 'the' is 'e'.
'pass'+'e'+'son'='PASSES ON'
'is' is the link.
Can you help me to learn more?
(Other definitions for passes on that I've seen before include "Hands to the next person" , "Dies; transmits" , "graduates" .)