A frozen mass of feces frequently found in the undergarments of particularly incompetent mountaineers.
After yet another seven summits failure, Joe's tent mate suffered the added indignity of having to remove a shit glacier from Joe's putrid underpants.
When someone takes a particularly stinky dump in an upstairs bathroom, so bad that the stench fills the upstairs & then comes rolling down the stairs, the slow-moving flow of stench downhill is called a "shit glacier".
The worst of which sometimes makes it all the way to the foot of the stairs.
"Man, I had to climb through a shit glacier to get to the upstairs restroom!"