Pour the last of delicious cordial (5)
I believe the answer is:
swarm
'pour' is the definition.
(synonyms)
'last of delicious cordial' is the wordplay.
'last of' suggests the final letters.
'cordial' becomes 'warm' (synonym).
The final letter of 'delicious' is 's'.
's'+'warm'='SWARM'
'the' is the link.
(Other definitions for swarm that I've seen before include "some setting up colony" , "Horde" , "Group of flies" , "Body of bees" , "Large cloud (of insects)" .)