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1. A special clay containing iron and manganese oxides, used as a pigment for oil and watercolor painting.
a. Raw sienna.
b. Burnt sienna.
[Short for terra-sienna, from Italian terra di Sienna, earth of Siena, after Siena.]
1. (Dyeing) a natural earth containing ferric oxide used as a yellowish-brown pigment when untreated (raw sienna) or a reddish-brown pigment when roasted (burnt sienna)
2. (Colours) the colour of this pigment. See also burnt sienna
[C18: from Italian terra di Siena earth of Siena]
1. an iron-bearing earth used as a yellowish brown pigment or, after roasting in a furnace, as a reddish brown pigment.
2. the color of such a pigment.
[1750–60; < Italian (terra di) Sien(n)a (earth of) Siena]