The most common and most likely answer to this crossword clue is the 6 letter word SURGED
I've seen this crossword clue in Financial Times
S
U
R
G
E
D
Buddy explains!
The straight part
We know that "Rose" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rose = surged.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 SURGED mean?
SURGED verb- To rush, flood, or increase suddenly.
- To accelerate forwards, particularly suddenly.
- To slack off a line.