Webster's Revised Unabridged Dictionary · 1913

Sinapine

Sinapine , noun

[Latin sinapi, sinapis, mustard, Greek {not transcribed}: compare French sinapine.]

(Chemistry) An alkaloid occurring in the seeds of mustard. It is extracted, in combination with sulphocyanic acid, as a white crystalline substance, having a hot, bitter taste. When sinapine is isolated it is unstable and undergoes decomposition.