He has a stab at making a label (7)
I believe the answer is:
sticker
'a label' is the definition.
('sticker' can be a synonym of 'label')
'he has a stab at' is the wordplay.
I cannot really understand how this works, but
'he' could be 'ker' and 'ker' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'making' is the link.
Can you help me to learn more?
(Other definitions for sticker that I've seen before include "Person with staying power" , "Gummed label" , "he soldiers on!" , "Adhesive label" , "problem" .)