Definition of "firn" [firn]

• Granular, partially consolidated snow that has passed through one summer melt season but is not yet glacial ice. Also called old snow. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The line that separates these two areas is called the firn limit or snow line."
• "Thus we must discriminate between two distinct parts of the ice fields; that is, first, the snow which originally fell—called firn in Switzerland—above the snow line, covering the slopes of the peaks as far as it can hang on to them, and filling up the upper wide kettle-shaped ends of the valleys forming widely extending fields of snow or firnmeere."
• "The glaciers that make up this alpine cryosphere are actually constantly moving "rivers of ice" that begin in their "accumulation zones" high on mountainsides, where snows fall and are compressed into "firn," the blue ice that gives glaciers their air of frozen purity."