a cliff or steep slope rising at one end of a glaciated valley.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for head wall
These little underground runlets are the same that glide over the head-wall, and are the head tributaries of the Ellis.
From the bowlders up the head-wall, and through the gate-way, the climb is arduous; and the way is not very distinctly marked.