noun
cobalt
KOH-bolt
noun
1
A hard, silvery-grey metallic chemical element (symbol Co, atomic number 27), used to make alloys and pigments.
"Cobalt is added to steel to make it more heat-resistant."
2
A deep, vivid blue colour, named after a pigment made from the metal.
"The ceramic bowl was glazed a striking cobalt."
How to Use Cobalt
Learner’s notesIn plain EnglishA metal used in alloys and batteries, and also the name of the rich blue colour associated with its compounds.
Common pairings
cobalt blue
cobalt mining
a cobalt alloy
Word Forms
cobalts plural
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Etymology
From German Kobalt, itself linked to Kobold ("goblin") — miners blamed mischievous spirits for cobalt ore, which looked like silver but poisoned them with arsenic fumes when smelted.