Added 10 October 2026 eupatorium noun Categories: PlantsObscure Words noun ! Definition from Wiktionary (CC BY-SA). More about eupatorium at Wordnik → Where our words come from → Any of the genus Eupatorium of perennial herbs. Origin From the genus name. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: thoroughworteuphrasiahempweedeuphorbeuphorbiaeuphorbiumboneseteyebrighteuphrasyfeverweedspurge Back to today's word