The most common and most likely answer to this crossword clue is the 7 letter word REGROUP
I've seen this crossword clue in Financial Times
R
E
G
R
O
U
P
More clues leading to the result REGROUP
- Rogue goes off in spin round rally
- Note Greek publishing outfit getting to assemble again
- . Roger turned up for rally
- Shuffle about with family
- Soldiers come of age, miss women, then get back together
- One cleaning up extra oxygen to make new order
- Gather scattered forces about school?
- Exterminator outflanking circle that’s about to rally
- Actively urge pro to join up again
- Give a party a new constitution, perhaps
Buddy explains!

The straight part
We know that "to assemble again" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to assemble again = regroup.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 REGROUP mean?
REGROUP verb- To pause and get organized before trying again.
- To group or categorize again.