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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
Connor Greene, Time, 9 Jan. 2026
But the colors, ranging from cyan to deepest cobalt, owe more to the geology of the archipelago and to the reflective quality of its pearlescent white sand.
—Henry Wismayer, Travel + Leisure, 7 Jan. 2026
Instead of relying on lithium, cobalt, or nickel, the system uses abundant iron and table salt on the cathode side, separated from molten sodium metal by a ceramic membrane that only conducts sodium ions.
—Tejasri Gururaj, Interesting Engineering, 6 Jan. 2026
New Atlas has previously reported on fast, inexpensive direct lithium extraction that could prevent supply crises, and a super-fast robotic system for dismantling EV batteries to extract lithium, cobalt, and metal foils.
—New Atlas, 31 Dec. 2025
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Cite this Entry
“Cobalt.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cobalt. Accessed 15 Jan. 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
