Home › Words › X › xylosteinxylosteinxylostein · noun — A bitter principle obtained from the berries of the fly honeysuckle (Lonicera xylosteum) and formerly used in medicine.Definition from Wiktionary (CC BY-SA 3.0).Among words judged in Lexicurio's Arena, xylostein ranks #11,404 of 43,061 for Qualifying.EtymologyFrom xylosteum + -in.nounA bitter principle obtained from the berries of the fly honeysuckle (Lonicera xylosteum) and formerly used in medicine.e.g.“Honeysuckle fruits contain valerianic acid and xylostein, which are irritant.” — 2008, Alexander Campbell, Michael Chapman, Handbook of Poisoning in Dogs and Cats:Definitions & examples from Wiktionary (CC BY-SA 3.0).