mar·cion·ite \-ˌnīt\noun alsomar·cion·ist\-_nə̇st\ (-s) Usage: usually capitalized Etymology: Late Latin marcionita, marcionista, from Marcion + Latin -ita -ite or Latin -ista -ist : a member of an anti-Judaic Gnostic sect that flourished from the 2d century to about the 7th century A.D.