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

Infused with mineral-rich silica and algae sourced from the Blue Lagoon itself, the kit revives tired skin, soothes irritation and leaves even the most rugged faces feeling spa-fresh. —Daniella Gray, MSNBC Newsweek, 4 June 2025

That’s one reason researchers and miners’ advocates have pushed for the new silica dust regulations, which would have cut allowable exposure in half. —Bob Ortega, CNN Money, 4 June 2025

For that reason, the researchers started by encasing the chemical molecules in durable silica nanoparticles. —Ben Coxworth may 26, New Atlas, 26 May 2025

The new rule was set to take effect in April, cutting the allowable level of silica dust in the air inside mines by half — to the limit already in place for other industries — and set stricter guidelines for enforcement. —Taylor Sisk, CNN Money, 26 May 2025

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