Fulgurite \Ful"gu*rite\, n. [L. fulguritus, p. p. of fulgurire
to strike with lightning, fr. fulgur lightning: cf. F.
fulgurite.]
A vitrified sand tube produced by the striking of lightning
on sand; a lightning tube; also, the portion of rock surface
fused by a lightning discharge.
[1913 Webster]