1. [syn: insulator, dielectric, nonconductor]
The Collaborative International Dictionary of English v.0.48:
Insulator \In"su*la`tor\, n.
1. One who, or that which, insulates.
2. (Elec. & Thermotics) A substance or object that insulates;
a nonconductor; as, polyurethane foam is a popular thermal
[1913 Webster +PJC]
WordNet (r) 3.0 (2006):
n 1: a material such as glass or porcelain with negligible
electrical or thermal conductivity [syn: insulator,
dielectric, nonconductor] [ant: conductor]