Source : Webster's Revised Unabridged Dictionary (1913)

Eucairite \Eu*cai"rite\, n. [Gr. ? seasonable, opportune; ?
   well, good + ? season.] (Min.)
   A metallic mineral, a selenide of copper and silver; -- so
   called by Berzelius on account of its being found soon after
   the discovery of the metal selenium.