What does frazil mean?
Frazil refers to fine, loose crystals of ice — typically thin, needle-like discs a few millimetres across — that form when water is cooled below its freezing point yet kept from solidifying into a solid sheet by turbulence. It appears most often in fast-flowing rivers and in the open waters of polar seas, where churning mixes the chilled water throughout its depth. To observers, frazil gives water a milky, slushy quality, and the collective formation is generally called frazil ice. Beyond its visual character, frazil matters practically: it adheres readily to submerged structures such as hydroelectric intakes, trash racks, and riverbed stones, where it can build up as anchor ice and disrupt operations. In glaciology it also marks the first stage in the growth of sea ice, eventually consolidating into pancake ice and young ice sheets. The word is largely technical, appearing in scientific literature, engineering reports, and polar studies.
nounFine, loose needles or plates of ice that form in turbulent, supercooled water, giving the water a slushy appearance; collectively known as frazil ice.
- Loose, needle-like ice crystals forming in turbulent, supercooled water, especially rivers and polar seas.
"The river's rapids churned with frazil as the supercooled water raced through the gorge."
"Hydro engineers monitor frazil buildup on intake screens during cold snaps."
"In Antarctic leads, frazil forms the first stage of new sea ice before it consolidates into pancake ice."
Before an iceberg even begins to grow, it starts as frazil — tiny icy needles swirling invisibly in water colder than freezing without being frozen.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of frazil
The word entered English from French usage in Canada, where it was recorded in connection with the icy slush observed in the St. Lawrence River and other turbulent northern waters. Its ultimate origin is not firmly established; some sources connect it to the French 'frais' (fresh or cool), but this link remains uncertain, so the precise linguistic ancestry should be treated cautiously. Frazil has been used in English-language scientific writing since at least the nineteenth century.
How frazil is actually used
A technical term used mainly in glaciology, limnology, and engineering contexts rather than everyday conversation; it describes both the individual crystals and, more commonly, the collective slush they form (usually written as 'frazil ice').
Easily confused with frazil
Fizzle refers to something that fails or peters out, whereas frazil refers to loose ice crystals formed in supercooled water.