Where does “Sundayism” come from?

Sundayism (English) comes from English sunday, from Middle English Sonday, from Old English sunnandæg, from Proto-Germanic *Sunnōn dag, from Latin dies Solis, from Latin sōl, from Proto-Indo-European sóh₂wl̥ — sun.

Sundayism (English): The conservative Christian evangelism of Billy Sunday (1862–1935), American baseball player and influential evangelist

Definitions

  1. The conservative Christian evangelism of Billy Sunday (1862–1935), American baseball player and influential evangelist

Ancestry of “Sundayism”, step by step

Sundayism traces back through two separate lines of ancestry.

via English sunday

StepLanguageWordMeaning
1EnglishsundayThe first day of the week in many religious traditions, and the seventh day of the week in systems using the ISO 8601 standard; the Christian Sabbath; it follows Saturday and precedes Monday
2Middle EnglishSondaySunday first day of the week
3Old EnglishsunnandægSunday
4Proto-Germanic*Sunnōn dag
5Latindies Solissun's day
6Latinsōl
7Proto-Indo-Europeansóh₂wl̥sun

via English ism

StepLanguageWordMeaning
1EnglishismAn ideology, system of thought, or practice that...
2English-ismUsed to form nouns of action or process or result...
3Latin-ismus-ism
4Ancient Greek-ισμόςForms abstract nouns
5Ancient Greek-μόςForms abstract nouns
6Proto-Indo-European-mósCreates action/result nouns from verb stems
Every word from Proto-Indo-European sóh₂wl̥Every word from Latin sōlEvery word from Latin dies Solis