oversteepening
/ˌəʊvəˈstiːp(ə)nɪŋ/Chiefly Physical Geography
noun
The increasing of a slope to a steepness greater than is normal or stable; especially the formation of a glacially oversteepened valley.
Origin
Early 20th century; earliest use found in Science. From over- + steepening adjective. Compare overdeepening and slightly earlier oversteepened.