Nearby in a cul de sac (5)
I believe the answer is:
close
'nearby' is the definition.
(similar in meaning)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for close that I've seen before include "on very affectionate terms" , "Near - conclusion" , "Near - shut" , "Imminent" , "Complete, a deal or case say" .)