Definition of ferrous in English:



  • 1(chiefly of metals) containing or consisting of iron.

    • ‘Good markets for ferrous metals, as well as copper and brass, have existed for years.’
    • ‘Except for aluminium and ferrous metal such as steel, the prices for most recyclable materials rests at the bottom of their historical ranges.’
    • ‘And while ferrous metals are certainly not out of the picture, even from a consumer's perspective, it's hard not to notice the increased use of aluminum and plastic.’
    • ‘Rockwell Automation, for example, has ‘equal-sensing’ inductive proximity sensors that can sense whether a metal is ferrous or non-ferrous.’
    • ‘It was their first firearm to take centerfire, reloadable cartridges, and it was their first firearm to use ferrous metal for the receiver.’
    • ‘Anglo American is also involved in mining gold, diamonds, coal and ferrous metal but platinum accounts for 12% of its total revenues and 20% of its income.’
  • 2Chemistry
    Of iron with a valency of two; of iron(II).

    Compare with ferric
    • ‘Chemically, Strain 121's respiration process reduces ferric iron to ferrous iron and forms the mineral magnetite, the source of most of the magnetic material deposited on Earth some two billion years ago.’
    • ‘Within the body iron exist in two oxidation states: ferrous or ferric.’
    • ‘However, prolonged flooding can be detrimental to bottomland vegetation by decreasing aerobic respiration, and producing and accumulating toxic levels of ferrous Fe, nitrates, sulfides, and Mn.’
    • ‘The ability of wetland plants to flourish in environments with high Fe concentrations has been attributed to the oxidation of soluble ferrous iron to insoluble ferric iron in the rhizosphere.’
    • ‘The color due to ferric iron is yellow, not green, and ferric iron is not driven off but rather is reduced in oxidation state to ferrous iron.’


Mid 19th century: from Latin ferrum iron + -ous.