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 smooth, solid stick glides on comfortably, with skin conditioners like glycerin and dimethicone to keep underarms soft, while silica absorbs surface moisture. —Christa Joanna Lee, Allure, 14 Aug. 2025

The former takes it from building sites to line her cat’s litter tray, while the latter steadily steals industrial silica from his workplace with the intention of ultimately starting his own glass-making business. —Guy Lodge, Variety, 1 Aug. 2025

While that hole likely formed in a single major explosive event, the newest thermal feature appears to have formed by multiple small events that initially threw rocks but later threw silica mud a short distance, creating a small pit that became filled with silica-rich water. —Julia Jacobo, ABC News, 16 July 2025

Local employees worked for three divisions: Compensation Analysis and Support, which provided scientific support for claims involving Department of Energy workers with cancer caused by exposure to radiation, beryllium and silica. —Patricia Gallagher Newberry, The Enquirer, 2 July 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