IPA: /ˌsuːpəˈsɛʃən/
KK: /ˌsuːpərˈsɛʃən/
The act of replacing or taking the place of something or someone else.
The new law will lead to the supersession of the old regulations.
Supersession → It is formed from "super-" (meaning above or over) and "sedere" (meaning to sit). The word refers to the act of sitting above or taking the place of something else.
Think of something that is 'above' ('super-') and 'sitting' ('sedere') in place of another — that's why supersession means taking the place of something.