firn
Firn (noun) means a form of old snow that has been through several cycles of melting and refreezing, leaving it made up of many small grains of ice; it holds far less water than slush from a snow-cone, and its hardness varies with recent and current weather.
Etymology
Borrowed from German Firn, which goes back through Alemannic German firn ("last year's") and Old High German firni ("old") to Proto-West Germanic [Term?], from Proto-Germanic *firnijaz, *fernaz ("foregoing, previous"), and ultimately Proto-Indo-European *per- ("forth, forward, across, through"). It is cognate with Old English fyrn ("former"), Old Norse forn ("old"), and Gothic ???????? (fairneis, "old").