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

Testing the new bio-glass The team compared their new bio-glass, plain silica glass, and a commercial dental bone substitute in the rabbit skull repair. —Aamir Khollam, Interesting Engineering, 23 Sep. 2025

Inside the furnace, a reaction takes place that rips the oxygen from the silica and sticks it to the carbon from the wood. —IEEE Spectrum, 22 Sep. 2025

The aluminum-creation process begins with bauxite ore, a raw material that contains desirable aluminum-rich minerals but also a host of impurities including silica and iron and titanium oxides. —New Atlas, 17 Sep. 2025

But the higher the silica content, the greater the propensity for damage when driving on gravel or rocky surfaces, so that very good rain tire will wear very rapidly if used away from paved roads. —Wes Siler, Outside, 16 Sep. 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