It's a wrench to move midterm (7)
I believe the answer is:
shifter
'it's a wrench' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'move midterm' is the wordplay.
I cannot quite see how this works, but
'move' could be 'shift' (shifting is a kind of moving) and 'shift' is found within the answer.
The remaining letters 'er' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'to' is the link.
Can you help me to learn more?
(Other definitions for shifter that I've seen before include "Mover of scenery" , "One who moves a thing" .)