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

Manufacturers pivoted toward lower- and zero-silica formulations. —Dr. Céline Gounder, CBS News, 12 Mar. 2026

Glass sponges build intricate, mesh-like skeletons out of silica — the same material used to make glass. —Ryan Brennan, Miami Herald, 11 Mar. 2026

These organisms build intricate skeletons out of silica, the same material used to make glass. —Ryan Brennan march 11, Kansas City Star, 11 Mar. 2026

The liquid bronzer also features light-diffusing silica that softly blurs texture, and antioxidant-rich elderberry pairs with soothing botanicals like evening primrose to help keep dry, mature skin comfortable. —Christa Joanna Lee, Allure, 5 Mar. 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