Shelter provided by unknown number in a squalid district (6)
I believe the answer is:
asylum
'shelter' is the definition.
(asylum is a kind of shelter)
'unknown number in a squalid district' is the wordplay.
'unknown number' becomes 'y' (I've seen this in other clues).
'in' means one lot of letters goes inside another.
'squalid district' becomes 'slum' (slum is a kind of district. I am not sure about the 'squalid' bit.).
'a'+'slum'='aslum'
'y' put inside 'aslum' is 'ASYLUM'.
'provided by' acts as a link.
Can you help me to learn more?
(Other definitions for asylum that I've seen before include "Place of refuge, once a mental institution" , "Shelter given to refugee" , "Haven or hospital for the mentally ill" , "Sanctuary or institution for mentally ill" , "Sanctuary or kind of hospital" .)