The most common and most likely answer to this crossword clue is the 6 letter word PURDAH
I've seen this crossword clue in The Guardian
P
U
R
D
A
H
More clues leading to the result PURDAH
- Turning up road on a hill, not bad for seclusion
- Horribly hard up in seclusion
- A doctor in residence perhaps pulled back hospital screen
- Hard up, wretched in seclusion
- Seclusion of hard-up criminal
- Screen brought to court erected around back of prisoner
- Hard-up eccentric in seclusion
- Desperately hard up in seclusion
Buddy explains!

The straight part
We know that "seclusion" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seclusion = purdah.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 PURDAH mean?
PURDAH noun- A curtain, especially as used to conceal and divide women from men and strangers in some Hindu or Muslim traditions.
- A striped cotton cloth which is used to make curtains.
- The state or system of social gender seclusion in some Muslim or Hindu communities.
- A long veil, or other all-enveloping clothing, worn by women in some Muslim societies.
- Secrecy, isolation.
- (UK politics) The period immediately before an election or referendum during which restrictions are in force on the activity of civil servants.