1. An object that functions as an ensign but differs from it in some respect, usually in appearance: Vexilloids are characteristic of traditional societies and often consist of a staff with an emblem; such as, a carved animal, at the top.

Vexilloids of the Roman Empire were sophisticated in design and usage. Animals were used on standards until 104 B.C. when the consul Marius ordered the eagle to become the sole standard of Roman legions. Names and wreaths of honor were included on some Roman vexilloids, while in later years the emperors insisted that their portraits be used.

2. Etymology: from the word vexillum, the only cloth flag apparently carried by the Romans, which is derived the word vexillology, the study of flag history and symbolism.