The most common and most likely answer to this crossword clue is the 9 letter word SPIRALLED
S
P
I
R
A
L
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E
D
Buddy explains!
The straight part
We know that "Grew" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case grew = spiralled.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 SPIRALLED mean?
SPIRALLED verb- To move along the path of a spiral or helix.
- To cause something to spiral.
- To increase continually.