IPA: /ˌpriːəˈreɪndʒmənt/
KK: /priˈɛrənʤmənt/
A plan or agreement that is made in advance before something happens.
The prearrangement of the event helped everything go smoothly on the day.
Prearrangement → It is formed from "pre-" (meaning before) and "arrangement" (from Old French *arangement*, meaning the act of arranging). The word "prearrangement" means the act of arranging something beforehand.
Think of doing something 'before' ('pre-') it is 'arranged' — that's why prearrangement means to set things up in advance.