Chambers errs about 'utility' (7)
I believe the answer is:
sinuses
'chambers' is the definition.
The definition and answer can be both body parts as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'errs about utility' is the wordplay.
'errs' becomes 'sins' (I can't justify this - if you can you should believe this answer much more).
'about' indicates putting letters inside.
'utility' becomes 'use' (use is a kind of utility).
'sins' placed around 'use' is 'SINUSES'.
Can you help me to learn more?
(Other definitions for sinuses that I've seen before include "Top spaces" , "Cavities in skull connecting with nostrils" , "Empty spaces" , "holes in the head" .)