Proposing to offer no sign of gratitude for jewellery (5)
I believe the answer is:
bling
'jewellery' is the definition.
(informal term for jewellery)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for bling that I've seen before include "Showy jewellery" , "glitzy jewellery" , "Jazzy" , "Showy jewels etc" , "Jewellery for show" .)