The word "syphilionthus" is a medical term. It is spelled /saɪfɪliˈɒnθəs/ in IPA phonetic transcription. The word is composed of two parts, "syphi" referring to "syphilis" and "anthus" meaning "flower." Therefore, "syphilionthus" can be defined as a skin eruption resembling a flower after a person has contracted syphilis. While the spelling of this word may appear complex, its pronunciation is relatively straightforward, especially when using IPA phonetic transcription.
A copper colored syphilide with branny scales.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.