Maybe the last one, Jack! (5)
I believe the answer is:
straw
'jack' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their base form.
Perhaps you can see an association between them that I don't see?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for straw that I've seen before include "Disastrously, it may be the last" , "Dried stalks for fodder" , "Thatching material" , "It's clutched at in desperation" , "Pale-yellow - through which one can drink" .)