IPA: //sʌkəˈdeɪniəm//
KK: /sʌkəˈdeɪniəm/
A thing that serves as a substitute for something else.
In the absence of fresh fruit, the store offered a succedaneum made from artificial flavors.
Succedaneum is formed from 'succedere' (meaning to follow after) and the suffix '-um' (a neuter noun ending in Latin). The term refers to a substitute or replacement that follows in place of something else.
Think of something that 'follows after' as a substitute — that's what succedaneum means.