The most common and most likely answer to this crossword clue is the 7 letter word SUBURBS
I've seen this crossword clue in The Daily Telegraph
S
U
B
U
R
B
S
Buddy explains!
The straight part
We know that "Dormitory accommodation" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dormitory accommodation = suburbs.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 SUBURBS mean?
SUBURBS noun- A residential area located on the outskirts of a city or large town that usually includes businesses that cater to its residents; such as schools, grocery stores, shopping centers, restaurants, convenience stores, etc.
- (by extension) The outer part; the environment.
- Any subdivision of a conurbation, not necessarily on the periphery.