Stops certain promotions (5)
I believe the answer is:
plugs
This might be a double definition.
'stops' is the first definition.
(plug is a kind of stop)
'certain promotions' is the second definition.
'plugs' can be an answer for 'promotions' (plug is a kind of promotion). I'm not certain of the 'certain' bit.
Can you help me to learn more?
(Other definitions for plugs that I've seen before include "Advertisements" , "Stops up" , "Advertises" , "Electrical connectors" , "stoppers" .)