katabasis
noun
ka·tab·a·sis
variants or catabasis
kəˈtabəsə̇s
plural katabases or catabases
-bəˌsēz
1
: a going or marching down or back : retreat
especially : a military retreat
the Russian anabasis and katabasis of Napoleon 
Thomas De Quincey
Thomas De Quincey the tragic and precipitate katabasis of the UN troops H. L. Ickes
H. L. Ickes 2
: a troparion sung after the two sides of the choir descend to the middle of the church at the end of each ode of the canon at matins in the Eastern Orthodox Church
Word History
Etymology
Greek katabasis descent, from katabainein to go down, from kata- cata- + bainein to go