(Science: chemical) a variety of lignite, of a very compact texture and velvet black colour, susceptible of a good polish, and often wrought into mourning jewelry, toys, buttons, etc. Formerly called also black amber.
(Science: zoology) jet ant, a blackish European ant (formica fuliginosa), which builds its nest of a paperlike material in the trunks of trees.
Origin: OF. Jet, jayet, f. Jaiet, jais, L. Gagates, fr. Gr.; so called from or, a town and river in Lycia
alternative forms: jeat, jayet.