azure

Etymology

From Middle English asure, from Old French azur, derived from Arabic لَازَوَرْد (lāzaward, “lapis lazuli”), dropping the l as if it were equivalent to the French article l’. The Arabic is from Classical Persian لاجورد (lājward, “lapis lazuli”), from the region of Lajward in Badakhshan. Compare with Italian azzurro and Spanish azul.

noun

1. (countable and uncountable) The clear blue colour of the sky; also, a pigment or dye of this colour.
   In robes of azure. 1815, William Wordsworth, Extracts from An Evening Walk
   For our blues we have the azures and ceruleans, lapis lazulis, the light and dusty, the powder blues, the deeps: royal, sapphire, navy, and marine […] 2014, William H. Gass, On Being Blue: A Philosophical Inquiry, page 59
   azure:
2. (heraldry) A blue colour on a coat of arms, represented in engraving by horizontal parallel lines.
   In Bb [Glover's Roll], the conventional letter B is used to indicate azure in most items. 1997, Brault, Early Blazon
   azure (heraldry):
3. (poetic) The unclouded sky; the blue vault above.
4. Any of various widely distributed lycaenid butterflies of the genus Celastrina.
5. Any of various Australasian lycaenid butterflies of the genus Ogyris.
6. Lapis lazuli.

adj

1. Sky blue; resembling the clear blue colour of the unclouded sky.
   When Britain first, at Heaven's command / Arose from out the azure main. 1740, James Thomson, Rule, Britannia!
2. Cloudless.
3. (heraldry) In blazon, of the colour blue.
   ‘I forget your coat of arms.’ ‘A human foot d’or, in a field azure; the foot crushes a serpent rampant whose fangs are imbedded in the heel.’ 1846, Edgar Allan Poe, The Cask of Amontillado

verb

1. (transitive) To colour blue.
   Our readers are aware that much of the sugar sold in many countries goes through an azuring treatment; blue is added to granulated sugar with the view of making it appear whiter than it actually is. 1907, The Sugar Beet, volume 28, page 271