the.com/insulator
The professional bouncer of physics, blocking electrons that didn't make the list.
means A material or device that resists the flow of electricity, heat, or sound, keeping it contained where it belongs.
from From Latin 'insula,' meaning 'island' — the same root that gave us 'isolate' and 'peninsula.' To insulate something is to make it an island, cut off from its surroundings; an insulator is the thing that builds the moat. The word entered English in the 18th century, riding the wave of early electrical experimentation.
glass twistGlass insulates until heated, then conducts electricity
diamond kingDiamond insulates electricity but conducts heat brilliantly
collector crazeAntique glass power-line insulators sell for thousands
superconductor flipSome insulators become superconductors near absolute zero
life saverRubber gloves keep electricians breathing around live wires