D defs.my
Entry 1 sense Webster, 1913

Rupert's drop

· Ru·pert's drop · IPA
01 n. A kind of glass drop with a long tail, made by dropping melted glass into water. It is remarkable for bursting into fragments when the surf…
  1. 1.
    A kind of glass drop with a long tail, made by dropping melted glass into water. It is remarkable for bursting into fragments when the surface is scratched or the tail broken; -- so called from Prince Rupert, nephew of Charles I., by whom they were first brought to England. Called also Rupert's ball, and glass tear. Also: Rupert's ball, glass tear