Make shorter using a spanner (7)
I believe the answer is:
abridge
'make shorter' is the definition.
'a spanner?' is the wordplay.
'spanner?' becomes 'bridge' (I've seen this before).
'a'+'bridge'='ABRIDGE'
'using' is the link.
(Other definitions for abridge that I've seen before include "Remove sections" , "Crop" , "Curtail" , "Big read (anag) - shorten text" , "Shorten by using fewer words" .)