noun
parting party; divorce party
A gathering held to mark a separation, such as leaving a workplace or ending a marriage. The divorce-party sense is a modern, somewhat informal extension.
退職する同僚のために離宴を開いた。
We held a farewell party for a colleague who was leaving the company.
最近は円満離婚のあと、友人を招いて離宴をする人もいるらしい。
These days, some people apparently throw a divorce party with friends after an amicable split.
Compound of 離 (separation) and 宴 (banquet, party). The exact historical derivation is uncertain, but the word is formed from standard Sino-Japanese elements.