Dithyrambic \dith-uh-RAM-bik\ , adjective;
1. Wildly enthusiastic
2. Wildly irregular in form
3. Of, pertaining to, or of the nature of a dithyramb
Dithyramb dates to the 1600's and comes from Latin dithyrambus which is derived from Greek dithyrambos, which is of unknown origin. In Greek it was 'a wild choric hymn, originally in honor of Dionysus or Bacchus' that was 'wild in character; a Baccanalian song.'
It sort of makes sense that a song sung to Dionysus, god of wine and fertility, would be a bit rambunctious!
Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Thursday, December 30
Etymologies come from the Oxford English Dictionary and/or Etymonline.com