Compresses, constricts (8)
I believe the answer is:
squeezes
I believe this is a double definition.
'compresses' is the first definition.
('squeeze' can be a synonym of 'compress')
'constricts' is the second definition.
('squeeze' can be a synonym of 'constrict')
(Other definitions for squeezes that I've seen before include "Compresses, or presses firmly" , "Shows of affection" , "for which one gets no credit" .)