quicksilver (n.)

common popular designation of metallic mercury, Middle English quik-silver, from late Old English cwicseolfor, literally "living silver," so called for its mobility, translating Latin argentum vivum (source also of Italian argento vivo), "living silver;" so called from its liquid mobility. See quick (adj.) + silver (n.). Similar formation in Dutch kwikzilver, Old High German quecsilbar, German quecksilber, French vif-argent, Italian argenta viva.

updated on March 06, 2021

Definitions of quicksilver from WordNet
quicksilver (n.)
a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures;
Synonyms: mercury / hydrargyrum / Hg / atomic number "
quicksilver (adj.)
liable to sudden unpredictable change;
a quicksilver character, cool and willful at one moment, utterly fragile the next
Synonyms: erratic / fickle / mercurial
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