'bling' originates from American English (slang), specifically the imitation word 'bling' (an onomatopoeic representation of a metallic sparkle or flash), where it imitated the sound/visual effect of light reflecting off jewelry.

'bling' emerged in US hip-hop slang in the early 1990s to name flashy jewelry or its sparkle; it later became a verb 'to bling' meaning 'to decorate with flashy items', and the past/p.p. form became 'blinged'.

Initially it referred to the shiny flash or the jewelry itself ('flashy sparkle'), but over time it also came to mean 'to decorate or embellish with flashy jewelry or ornaments'.