1
: a magnetic metallic element that is used especially in alloys, in batteries, and as a pigment in paint and glass see Chemical Elements Table
2

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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

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As European electric vehicle adoption accelerates and stricter battery recycling rules loom, securing domestic access to critical minerals like lithium, nickel, and cobalt has shifted from an environmental goal to a national security priority. Mrigakshi Dixit, Interesting Engineering, 7 Aug. 2026 The shallowest sections near the coast appear bright aquamarine, the deepest shift toward cobalt or lapis, and a mottled turquoise fills the space between. Sarah Bruning, Travel + Leisure, 6 Aug. 2026 Thursday's move, however, came only after the news that Democratic Republic of Congo was officially banning copper and cobalt concentrates exports to encourage more domestic processing. Deena Zaidi, CNBC, 6 Aug. 2026 Colored denim continues its momentum for the cooler months, shifting from the soft rose tones and sandy neutrals of spring 2026 to high-impact hues, like the cobalt pair seen at Chloé and a vibrant red at Isabel Marant. Kristina Rutkowski, Vogue, 5 Aug. 2026 See All Example Sentences for cobalt

Word History

Etymology

German Kobalt, alteration of Kobold, literally, goblin, from Middle High German kobolt; from its occurrence in silver ore, believed to be due to goblins

First Known Use

circa 1872, in the meaning defined at sense 1

Time Traveler
The first known use of cobalt was circa 1872

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Cite this Entry

“Cobalt.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cobalt. Accessed 10 Aug. 2026.

Kids Definition

: a tough shiny silver-white magnetic metallic element that is found with iron and nickel and is used especially in alloys see element
Etymology

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

: a tough lustrous silver-white magnetic metallic element that is related to and occurs with iron and nickel and is used especially in alloys
symbol Co
see Chemical Elements Table

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