The most common and most likely answer to this crossword clue is the 6 letter word COHERE
I've seen this crossword clue in Financial Times
C
O
H
E
R
E
More clues leading to the result COHERE
- Famous runner carrying her stick
- Leave me out of summons, to be consistent
- Stick in this place with commanding officer
- Business woman’s hope finally to stick together
- Stick together in this place having joined firm
- Bind helium in nucleus
- Stick ambassador in the middle
- Deadly gas in our vicinity – stick together!
- Stick around to get love present
- Business in this place, form a close association
Buddy explains!

The straight part
We know that "stick together" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stick together = cohere.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 COHERE mean?
COHERE verb- To stick together physically, by adhesion.
- To be consistent as part of a group, or by common purpose.