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

Now, a deeper look suggests a much broader assortment of material from the outside world — silica, metals, soot and other debris — is getting through. — Ariana Eunjung Cha, Washington Post, 22 Oct. 2026

Engineers kept signal loss low within standard physical dimensions by using ultra-pure synthetic silica during production. — Mrigakshi Dixit, Interesting Engineering, 19 Oct. 2026

From their sample, around one-third of extreme debris disks are silica-rich disks. — Robert Lea, Space.com, 6 Oct. 2026

Ripple Hollow, another roadless area, contains silica deposits. — Christiana Freitag, Chicago Tribune, 4 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