arceus = saucer | Bulbagarden

Arceus's name may come from the words arch (highest) and deus, which is Latin and Greek for god. It may also have a root in the Latin word arcanus, which means secret; sacred mystery. Or Arceus's name which was pronounced as (Arh-keus) maybe a combination of "Arch" and a mispronounced word "Chaos".

Arceus's name may also come from the word archaic (ancient), which comes from the Greek arkhaios, and is derived from the ancient Greek word for "beginning", arkhē. It could have also come from the Latin word archetypus (original). Alternatively, Arceus's name can be seen as a portmanteau of Zeus, the most powerful of Greek gods and arch (highest).