IPA: //poʊstˈnʌp.tʃu.əl//
KK: /ˈpoʊstˌnʌpʧuəl/
Relating to the time or events that happen after a marriage has taken place.
They signed a postnuptial agreement to clarify their financial responsibilities.
Postnuptial → It is formed from "post-" (meaning after) and "nuptialis" (from Latin "nuptiae", meaning marriage). The word "postnuptial" refers to events or agreements that occur after marriage.
Think of 'after' ('post-') a 'marriage' ('nuptiae') — that's what postnuptial means.