saturnalian

noun, plural Sat·ur·na·li·a, Sat·ur·na·li·as.

1. (sometimes used with a plural verb) the festival of Saturn, celebrated in December in ancient Rome as a time of unrestrained merrymaking.
2. (lowercase) unrestrained revelry; orgy.

noun plural -lia or -lias

1. an ancient Roman festival celebrated in December: renowned for its general merrymaking
2. (sometimes not capital) a period or occasion of wild revelry

n.time of merrymaking, 1590s, from Latin Saturnalia, ancient Roman festivals of Saturn (held in December), a time of merrymaking for all, from neuter plural of adjective Saturnalis “pertaining to Saturn,” from Saturnus (see Saturn). They correspond to the Greek Kronia. The extended sense of “period of unrestrained revelry” is first attested 1782. Related: Saturnalian.