IPA: /ˌsuːpəˈsiːd/
KK: /ˌsuːpərˈsiːd/
To take the place of something or someone, especially because it is considered better or more modern.
The new technology will supersede the old methods of communication.
Past: superseded
Past Participle: superseded
Supersede is formed from "super-" (meaning above or over) and "sedere" (meaning to sit). The word describes the act of sitting above or taking the place of something else, thus replacing it.
Think of something that 'sits above' ('super-') and 'takes the place of' ('sedere') something else — that's why supersede means to replace.