Stick to imitation jewellery (5)
I believe the answer is:
paste
'stick to' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for paste that I've seen before include "Food prepared for spreading" , "Food for spreading or fixative" , "Soft, malleable material - stick" , "Adhesive gum" , "Fix with adhesive" .)