Narrow thoroughfares or wide streams? (6)
I believe the answer is:
broads
'narrow thoroughfares' is the definition.
(B-roads)
'wide streams?' is the wordplay.
'wide' becomes 'broad' (synonyms).
'streams?' becomes 's' (this might be a standard abbreviation of which I'm unaware).
'broad'+'s'='BROADS'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for broads that I've seen before include "found in part of eastern England" , "Wetland" , "Norfolk holiday area" , "Old coins" .)