Boron, arsenic, and antimony, among other substances, are used as dopants when added to a pure semiconductor material to alter its electrical characteristics.
Artificially produced gemstones[?] (such as Ruby (gemstone)) usually contain a dopant to identify them as such.
... the admiration of Count Vronsky to the jealously of Dolly's sister Katarina (Kitty) whom he has previously been courting.
As the novel opens, Stiva's friend Levin has ...