The most common and most likely answer to this crossword clue is the 9 letter word CIRCULATE
C
I
R
C
U
L
A
T
E
Buddy explains!
The straight part
We know that "Spread" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case spread = circulate.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 CIRCULATE mean?
CIRCULATE verb- To move in circles or through a circuit
- To cause (a person or thing) to move in circles or through a circuit
- To move from person to person, as at a party
- To spread or disseminate
- To become widely known
- Of decimals: to repeat.