Devla (also called O Raj, Deloro and DEl) is the name of God in the Romani religion. Devla was mistaken with the devil or Satan by the general public when the Romani tribes arrived in Europe during the 14th century. Devla is often mentioned in Roma folk songs.
When Romani is translated into English, the word Devla is usually translated as "God", as shown here in this Romani language textbook:
Romani Christians also refer to the Christian God as Devla or Del when they speak Romani, although these Romani words existed in traditional Romani folk beliefs and in the Romani language centuries before any Romani adopted Christianity. That is, "Devla" is a common noun meaning a "God" It is based on the Sanskrit word "Deva" which is related to the Latin words "deus" (god) and "divinus" (godly, godlike). "DEl" or "O DEl" is based on the Israelite word "El Elyon" meaning "God Most High", and similarly in the Septuagint as "Ο ΘΕΟΣ Ο ΥΨΙΣΤΟΣ" ("God the highest").
There is a common misconception among many Gadje (non-Roma persons) that Romani worship the devil. This is only because the word Devla sounds a lot like the word devil but is actually a false cognate. The Romani word for devil, or Satan, is actually "Beng".