Holds up operations on the street
I believe the answer is:
stops
'holds up' is the definition.
(I've seen this in another clue)
'operations on the street' is the wordplay.
'operations' becomes 'ops' (abbreviation).
'on' says to put letters next to each other.
'the street' becomes 'st' (abbreviation).
'ops' put after 'st' is 'STOPS'.
(Other definitions for stops that I've seen before include "Discontinues" , "Halts" , "Ends" , "Posts (anag.)" , "Checks" .)