Mumetal

[ moo-met-l, myoo- ]
/ ˈmuˌmɛt l, ˈmyu- /

noun

an alloy containing nickel, iron, and copper, characterized by high magnetic permeability and low hysteresis losses.

Origin of Mumetal

formerly a trademark; mu (representing the Greek letter, a conventional symbol for permeability) + metal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019