Less than marginal, that's very clear (3)
I believe the answer is:
gin
'very clear' is the definition.
The definition and answer can be both to do with contact as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'less than marginal' is the wordplay.
'less' indicates the answer is hidden within the clue (the clue less some of the letters in it).
'GIN' is hidden in the letters of 'than marginal'.
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for gin that I've seen before include "It often gets mixed up with this" , "Alcoholic drink once called mother's ruin" , "Spirit drink" , "Spirit; cotton machine" , "Alcoholic drink made from juniper berries - it's a trap" .)