silica

noun

sil·​i·​ca ˈsi-li-kə How to pronounce silica (audio)
: the dioxide of silicon SiO2 occurring in crystalline, amorphous, and impure forms (as in quartz, opal, and sand respectively)

Examples of silica in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Diatoms, fed by that upwelling material, bloom, die, and sink as a pale layer of silica—a layer that’s thicker in cool, dry years when the mixing season runs long. — Jacek Krywko, ArsTechnica, 9 Aug. 2026 Common additives and fillers in saffron capsule supplements include rice powder, silica, stearic acid and acacia gum. — Bestreviews, Chicago Tribune, 7 Aug. 2026 But the decline in cases has been reversed, and experts blame toxic silica dust that is now more common in mines. — Brittney Melton, NPR, 5 Aug. 2026 Heavy metals Hynek noted that Martian dust is known to contain various carcinogens, such as silica and numerous heavy metals. — Leonard David, Space.com, 5 Aug. 2026 See All Example Sentences for silica

Word History

Etymology

New Latin, from Latin silic-, silex hard stone, flint

First Known Use

circa 1801, in the meaning defined above

Time Traveler
The first known use of silica was circa 1801

Phrases Containing silica

Rhymes for silica

See All Rhymes for silica

Browse Nearby Words

silic-
silica
silica aerogel
See all Nearby Words

Cite this Entry

“Silica.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/silica. Accessed 14 Aug. 2026.

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Kids Definition

silica

noun
sil·​i·​ca ˈsil-i-kə How to pronounce silica (audio)
: a compound that consists of the dioxide of silicon and occurs in various forms (as in quartz, opal, and sand)

Medical Definition

silica

noun
sil·​i·​ca ˈsil-i-kə How to pronounce silica (audio)
: the dioxide of silicon SiO2 that is used as an ingredient of simethicone and that occurs naturally in crystalline, amorphous, and impure forms (as in quartz, opal, and sand respectively)

called also silicon dioxide

More from Merriam-Webster on silica

Nglish: Translation of silica for Spanish Speakers

Britannica.com: Encyclopedia article about silica

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