Dictionary.com
definitions

frazil

[frey-zuh l, fraz-uh l, fruh-zeel, -zil]
noun
  1. ice crystals formed in turbulent water, as in swift streams or rough seas.

Origin of frazil

1885–90, Americanism; < Canadian French frasil, frazil, fraisil, French fraisil coal cinders, Old French faisil
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for frazil

frazil

noun
  1. small pieces of ice that form in water moving turbulently enough to prevent the formation of a sheet of ice

Word Origin for frazil

C19: from Canadian French frasil, from French fraisil cinders, ultimately from Latin fax torch
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012