sienna Meaning, Definition & Usage

  1. noun an earth color containing ferric oxides; used as a pigment

WordNet

Si*en"na noun
Etymology
It. terra di Siena, fr. Siena in Italy.
Definitions
  1. (Chem.) Clay that is colored red or brown by the oxides of iron or manganese, and used as a pigment. It is used either in the raw state or burnt.

Webster 1913