n.
Pronunciation: ˌ p ə r- ˌ mi- ' ti-v ə -t ē , -m ə -
Function: noun
Etymology: 1 permit + -ivity (as in selectivity )
Date: 1887
: the ability of a material to store electrical potential energy under the influence of an electric field measured by the ratio of the capacitance of a capacitor with the material as dielectric to its capacitance with vacuum as dielectric ― called also dielectric constant