silica

noun

sil·​i·​ca ˈsi-li-kə 

: 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

Cosentino and Caesarstone promote lines of recycled and low-silica slabs. — The New York Times News Service Syndicate, San Diego Union-Tribune, 7 Nov. 2026

Turbine blades are built from silica-rich fiberglass bound together by carbon-dense resin. — Mrigakshi Dixit, Interesting Engineering, 6 Nov. 2026

Plus, there’s silica to softly blur the look of pores and texture without hindering your glow. — Christa Joanna Lee, Allure, 28 Oct. 2026

New research is exploring whether the materials dirty air carries, such as silica, metals, soot and other debris, could be physically changing the brain. — Ariana Eunjung Cha, Washington Post, 26 Oct. 2026

Word History

Etymology

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

First Known Use

circa 1801, in the meaning defined above

Phrases Containing silica

• silica gel
• vitreous silica

Rhymes for silica

• basilica

Kids Definition

silica

noun

sil·​i·​ca ˈsil-i-kə 

: 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 

: 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