Throttle and start to reverse in street corner (8)
I believe the answer is:
strangle
'throttle' is the definition.
('strangle' can be a synonym of 'throttle')
'start to reverse in street corner' is the wordplay.
'start to' suggests taking the first letters.
'in' indicates putting letters inside.
'street' becomes 'st'.
'corner' becomes 'angle' (I've seen this before).
The first letter of 'reverse' is 'r'.
'st'+'angle'='stangle'
'r' going within 'stangle' is 'STRANGLE'.
'and' is the link.
(Other definitions for strangle that I've seen before include "Choke to death" , "cut off supply of air" , "Smother" , "Kill by squeezing the throat" , "gag" .)