Definition of iron mole in English:

iron mole

noun

rare
  • A spot or stain on cloth, paper, etc., caused by iron rust or ink containing iron salts.

Origin

Late 16th century; earliest use found in John Lyly (1554–1606), writer and playwright. From iron + mole.

Pronunciation

iron mole

/ˌʌɪən ˈməʊl/