Prima Nocta is the right of a king to take and sleep with any bride on the night before her wedding. Originally, PrimoNocte referred to a free day in ancient Rome which included both 12am-2am and 3pm-5pm on that day. The word “nocturn” or “night” was later replaced by “nocte”. It’s use in this phrase is from the Latin for this period of time.
Since feudal times, King has large had Primo Nochte rights over virginal women who were still living at their parents’ homes under emotional ties with them but not legally part of their household.