Webster's Revised Unabridged Dictionary · 1913

Leyden jar

Leyden jar (lī"d'n jar"; 277) , noun

(Electricity) A glass jar or bottle used to accumulate electricity. It is coated with tin foil, within and without, nearly to its top, and is surmounted by a brass knob which communicates with the inner coating, for the purpose of charging it with electricity. It is so named from having been invented in Leyden, Holland.

Also: Leyden phial