Where does “sendiulo” come from?

sendiulo (Esperanto) comes from Esperanto Dio, from Italian Dio, from Latin Deus, from Latin dẹ̄vos, from Old Latin deivos, from Proto-Italic deiwos, from Proto-Indo-European deywós, from Proto-Indo-European dyew- — to be bright; sky, heaven.

sendiulo (Esperanto): a godless person, an atheist