Jamesonite Ja"me*son*ite, n. [From Prof. Jameson, of Edinburgh.] (Min.) A steel-gray mineral, of metallic luster, commonly fibrous massive. It is a sulphide of antimony and lead, with a little iron., Jamestown weed James"town` weed` (Bot.) The poisonous thorn apple or stramonium (Datura stramonium), a rank weed early noticed at Jamestown, Virginia. See Datura. Note: This name is often corrupted into jimson, jimpson, and gympsum.