The most common and most likely answer to this crossword clue is the 12 letter word ANASTOMOSING
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The straight part
We know that "Networking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case networking = anastomosing.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 ANASTOMOSING mean?
ANASTOMOSING verb- (of streams and rivers, blood vessels, etc) To join (two or more things) by anastomosis, to interconnect forming a network.
- (of rivers, blood vessels, etc) To join by anastomosis.
- Fused together in a vein-like network; used to describe mushroom gills that are interconnected with veins.
- Networked into irregularly branching and reconnecting veins of ore.