Etymograph

English

electret

Blend of electricity + magnet.

A blend of electricity + magnet

Middle English magnete ‘lodestone’

English magnet

Today it means

noun A solid dielectric having a quasi-permanent charge; usually a metallized film; used in electroacoustic and electromechanical transducers and in air filters.

Language periods are conventional ranges, not dates for this word.

Etymograph / electret