/in"seuh lay'teuhr, ins"yeuh-/ , n.
1. Elect.
a. a material of such low conductivity that the flow of current through it is negligible.
b. insulating material, often glass or porcelain, in a unit form designed so as to support a charged conductor and electrically isolate it.
2. a person or thing that insulates.
[ 1795-1805; INSULATE + -OR 2 ]