Block and bar (4)
I believe the answer is:
stop
I believe this is a double definition.
'block' is the first definition.
(synonyms)
'bar' is the second definition.
(I've seen this before)
'and' acts as a link.
(Other definitions for stop that I've seen before include "Plug - organ knob - bus halt - period" , "break" , "Discontinue (an action)" , "Pack it in - bar" , "End or pause" .)