See under arsenic trisulfide.
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a yellow or red crystalline substance, As2S3, occurring in nature as the mineral orpiment, and used as a pigment (king's yellow) and in pyrotechnics.
Origin of arsenic trisulfide
First recorded in 1905–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019