copperas

noun

cop·​per·​as ˈkä-p(ə-)rəs How to pronounce copperas (audio)
: ferrous sulfate

Word History

Etymology

Middle English coperas, from Anglo-French coperose, from Medieval Latin cuprosa, probably from aqua cuprosa, literally, copper water, from Late Latin cuprum

First Known Use

14th century, in the meaning defined above

Time Traveler
The first known use of copperas was in the 14th century

Dictionary Entries Near copperas

Copper Age

copperas

copperas black

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Cite this Entry

“Copperas.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/copperas. Accessed 1 Dec. 2024.

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Medical Definition

copperas

noun
cop·​per·​as ˈkäp-(ə-)rəs How to pronounce copperas (audio)
: a green hydrated ferrous sulfate FeSO4·7H2O used especially in making inks and pigments
—used especially of commercial grades not to be used internally
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