The most common and most likely answer to this crossword clue is the 8 letter word BATHROOM
I've seen this crossword clue in The Daily Telegraph
B
A
T
H
R
O
O
M
More clues leading to the result BATHROOM
- American privy to harm boy briefly unleashed
- Where to go brush trousers at hotel
- Privy to American airline informally employing mantra
- Good time to cover a royal seat, wiping one for John’s chamber
- Place for washing cleaner clothes at hospital
- Ladies maybe in place where spa water is available?
- City with west-facing heath, setting for soap action?
- Where to get cleaner putting brush around at hotel
- Barely used part of the house
- Convenience to Americans of English city upsets Muslim
Buddy explains!

The straight part
We know that "Barely used part of the house" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case barely used part of the house = bathroom.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 BATHROOM mean?
BATHROOM noun- A room containing a shower and/or bathtub, and (typically but not necessarily) a toilet.
- A lavatory: a room containing a toilet and (typically but not necessarily) a bathtub.