Characters line street wanting work (7)
I believe the answer is:
letters
'work' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'characters line street' is the wordplay.
'characters' indicates an anagram.
'line' becomes 'l' (used when specifying particular lines from a poem).
'l'+'street'='lstreet'
'lstreet' anagrammed gives 'LETTERS'.
'wanting' acts as a link.
Can you help me to learn more?
(Other definitions for letters that I've seen before include "...as, for example" , "They may indicate a degree" , "Literary culture" , "They are bound to look after tenants" , "eg E G" .)