Thoroughgoing street half cut off regularly in city (6)
I believe the answer is:
strict
'thoroughgoing street half cut off regularly in city' is the definition.
I can't tell whether this definition defines the answer.
'thoroughgoing street half cut off' is the wordplay.
'thoroughgoing street' becomes 'st' (abbreviation. I am not sure about the 'thoroughgoing' bit.).
'half' means to take half the letters.
'cut off' becomes 'abstrict' (abstricting is a kind of cutting off).
'abstrict' with half the letters taken is 'rict'.
'st'+'rict'='STRICT'
Can you help me to learn more?
(Other definitions for strict that I've seen before include "Severe, stern" , "Hard" , "Rigidly enforced" , "Rigidly accurate" , "Allowing no deviation from a standard" .)