Jet black is the deepest possible black. Jet black hair, painted jet black, jet black and shining.
Jet is a real stone, a kind of fossilised wood, and it was carved for mourning jewellery. Nothing in ordinary life is truly black, so jet black usually describes something dark and glossy.
1adjectivejet blackThe deepest possible black.
“Her hair was jet black and cut straight across.”
jet black is a colour.
Also accepted in games: jet-black
jet-black comes from jet + black.
Etymology from Wiktionary, CC BY-SA
Practised in Colours & Patterns