The name Marcellus is a boy's name of French origin meaning "young warrior". Marcellus and is often added to lists like Cool Boy Names From Ancient Cultures and discussed in our forums with posts like "Quick Question Thread?!".
From the experts:
This ancient Roman family name, first borne by the distinguished Marcus Claudius Marcellus and later by two popes, is a possibilty in the hot new category of names from antiquity.