French word ci-dessous comes from French dessous, French ci (Here. This.)

Detailed word origin of ci-dessous

Dictionary entry	Language	Definition
dessous	French (fra)	Under; beneath Disadvantage. Underside; bottom (women's) underwear. Hidden agenda Underneath; beneath.
ci	French (fra)	Here. This.
ci-dessous	French (fra)	Below, underneath (under this point).