Definition of Mumetal in English:

Mumetal

(also Mu-metal)

noun

Engineering
  • Any of a series of nickel-iron alloys containing approximately 75–78 per cent nickel, 4–6 per cent copper, and 1½–2 per cent chromium by weight, which are used to make transformer cores and magnetic shields because of their high permeability and low hysteresis loss in weak magnetic fields. [A trademark in the United Kingdom.]

Origin

1920s; earliest use found in The Trade Marks Journal. From the name of the Greek letter μ + metal.

Pronunciation

Mumetal

/ˈmjuːmɛt(ə)l/