Get topless to make an impression (4)
I believe the answer is:
etch
'make an impression' is the definition.
(I've seen this before)
'get topless' is the wordplay.
'get' becomes 'fetch' ('fetch' can be a synonym of 'get').
'topless' means to remove the first letter.
'fetch' with its first letter removed is 'ETCH'.
'to' is the link.
(Other definitions for etch that I've seen before include "Use acid to cut design" , "Carve into surface, impress deeply" , "Design on metal or glass using acid" , "Design by eating out" , "Cut lines with acid" .)