sēˈenə noun
( -s )
Etymology: short for earlier terra-sienna, modification of Italian terra di Siena earth of Siena, from terra earth (from Latin) + di of (from Latin de from, away) + Siena, Italy — more at de- , terrace
: any of various earthy substances that are brownish yellow when raw and orange red to reddish brown when burnt, that in general are darker in color and more transparent in oils than ochers, that occur in limonites, and that are used as pigments for oil stains as well as paints — compare iron oxide , umber