Bucket down (4)
'bucket down' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for teem that I've seen before include "Bear" , "Bucket down" , "stream" , "Swarm around meet" , "numerous" .)
(Other definitions for pour that I've seen before include "(Of rain) fall heavily" , "16 [CATS AND DOGS]" , "Tip liquid from container" , "Dispense tea - rain hard" , "bucket" .)