Cut corner initially in narrow street (5)
I believe the answer is:
lance
'cut' is the definition.
(I've seen this before)
'corner initially in narrow street' is the wordplay.
'initially' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'narrow street' becomes 'lane' (a lane is a narrow road).
The first letter of 'corner' is 'c'.
'c' going into 'lane' is 'LANCE'.
(Other definitions for lance that I've seen before include "steel" , "Knightly weapon" , "Weapon of knights of old" , "Shafted weapon used on horseback" , "Horseman's long weapon" .)