The clue to the true meaning of the acclaimed Yoruba word Olodumare (usually cleaved into O-ni-Odumare) lies in the similarity of the word Odumare and the word Osumare. Osu means ‘something round’ whilst Odu means ‘a big bowl’; the word ‘mare’ is common to both thus suggesting that ‘mare’ existed in two distinguishable versions: the ‘Osu’ version and the ‘Odu’ version. What constituted the ‘Odu’ version were two phenomena described by Ellis in his 1894 book. The first was an optical phenomenon, visible to the naked eye as large halo encircling the sun or moon. The second were bright celestial bodies: Sirius appeared as the brightest star in the night sky between November and April whilst the ‘Milky Way’ appeared as a hazy luminous white band across the sky on dark nights. It was the Christian clergy that converted Odumare of Yoruba astronomy to Olodumare, the sky-god.
Olodumare is often used interchangeably with Eledumare but the etymology of Eledumare is totally different. The ‘du’ in Eledumare is a verb meaning ‘to compete’ making ‘Eledu’ the competitor or rival, which made Eledu a type of ‘mare’ aside from Osumare.