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The metallic element "cobalt" ultimately draws its name from folklore. In Middle High German, "kobolt" denoted a usually helpful household elf that engaged in nasty pranks only when it was offended. Later, early Modern German Kobold came to refer to a variety of less helpful goblins inhabiting fields and mountains. The variant "Kobolt" in the 16th century was applied by German miners to ores containing the metal cobalt, which they considered to be worthless; they believed that mountain goblins had spoiled adjacent silver ores, or had stolen the silver within the ore. The metal itself in relatively pure form was not produced and described until the 17th century, when "cobalt," with its first letter influenced by New Latin cobaltum, became part of the international language of science.
Examples of cobalt in a Sentence
Neetika Walter, Interesting Engineering, 27 Apr. 2026
While riding through London in the Gold State Coach during her Golden Jubilee in 2002, the Queen was spotted in a light blue coat and a cobalt hat.
—Andrea Wurzburger, PEOPLE, 25 Apr. 2026
From all these locations, Regulus will disappear behind the moon's dark limb against a cobalt-blue sky during nautical or late twilight, with the sun at least 12 degrees below the horizon.
—Joe Rao, Space.com, 24 Apr. 2026
Critical minerals include lithium, cobalt, nickel, and graphite — key components of the lithium-ion batteries in smartphones, EVs, and the grid-scale storage systems that hold solar and wind power for later use.
—Big Think, 22 Apr. 2026
See All Example Sentences for cobalt
Cite this Entry
“Cobalt.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cobalt. Accessed 28 Apr. 2026.
Copy CitationKids Definition
from German Kobalt "cobalt," an altered form of Kobold, literally, "goblin"; so called because its appearance in silver ore was thought to have been the work of goblins who left it in place of silver which they stole
Medical Definition
cobalt
noun
