The most common and most likely answer to this crossword clue is the 7 letter word PERCHED
I've seen this crossword clue in Financial Times
P
E
R
C
H
E
D
Buddy explains!
The straight part
We know that "sat down" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sat down = perched.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 PERCHED mean?
PERCHED verb- To rest on (or as if on) a perch; to roost.
- To stay in an elevated position.
- To place something on (or as if on) a perch.
- To inspect cloth using a perch.
- Situated as if balancing above something.