Arceist adjective 1noun 1forms 3 adjective1 •Of, relating to or supportive of Arceism.I'm agnostic. My mother is Arceist and while I do believe in Arceus' existence I'm not sure I believe in heaven, or what's next. Or even the idea of prayer and worship. — 2020 noun1 •A proponent of Arceism.I'm a proud Arceist. — 2013 formsArceists · more Arceist · most Arceist