The most common and most likely answer to this crossword clue is the 6 letter word OSMOSE
I've seen this crossword clue in The Daily Telegraph
O
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More clues leading to the result OSMOSE
Buddy explains!
The straight part
We know that "Diffuse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case diffuse = osmose.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 OSMOSE mean?
OSMOSE verb- To diffuse by osmosis.
- To cause to diffuse by osmosis.
- The net movement of solvent molecules, usually water, from a region of lower solute concentration to a region of higher solute concentration through a partially permeable membrane.
- Picking up knowledge accidentally, without actually seeking that particular knowledge.