Compresses, in a way (4)
I believe the answer is:
zips
'compresses in a way' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for zips that I've seen before include "Locking devices with toothed edges" , "Slide fasteners" , "speeds" , "Dispatches" , "Toothed fasteners" .)