The most common and most likely answer to this crossword clue is the 8 letter word TORRENTS
I've seen this crossword clue in The Daily Telegraph
T
O
R
R
E
N
T
S
Buddy explains!
The straight part
We know that "They pour" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they pour = torrents.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TORRENTS mean?
TORRENTS noun- A violent flow, as of water, lava, etc.; a stream suddenly raised and running rapidly, as down a precipice.
- A large amount or stream of something.
- (file sharing) A set of files obtainable through a peer-to-peer network, especially BitTorrent.