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

The affected workers identified in the study reported 16 to 25 years of silica dust exposure while on the job. — Clara Harter, Los Angeles Times, 12 Aug. 2026

Used in skincare, silica is said to improve skin texture, support collagen production, and promote elasticity. — Evie Carrick, Travel + Leisure, 12 Aug. 2026

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

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