Of copper with a valence of one; of copper(I)
- ‘The second is a group of cuprous [copper] oxide minerals, and ‘crepitus’ is an interesting medical word with two meanings that appear in the OED - with none in Webster's.’
- ‘Oxygen may be found as a free gas or as cuprous oxide.’
- ‘These reactions depend on the ability of the reducing sugar to convert cupric sulfate to cuprous oxide with a resulting color change.’
- ‘Under magnification, these altered surfaces do not exhibit the naturally occurring corrosion layers, such as red cuprous oxide and green, basic copper carbonate, that might be expected.’
- ‘The material is a cuprous iron alloy with high carbon and a manganese sulfide additive.’
Mid 17th century: partly directly from late Latin cuprum copper (reinforced by cupric) + -ous.
We take a look at several popular, though confusing, punctuation marks.