DICT.TW Dictionary Taiwan

 Jet, n.  [written also jeat, jayet.] Min. A variety of lignite, of a very compact texture and velvet black color, susceptible of a good polish, and often wrought into mourning jewelry, toys, buttons, etc. Formerly called also black amber.
 Jet ant Zool., a blackish European ant (Formica fuliginosa), which builds its nest of a paperlike material in the trunks of trees.