Vexillum n. : A flag or standard.

Vexillum n. : A company of troops serving under one standard.

Vexillum n. : A banner.

Vexillum n. : The sign of the cross.

Vexillum n. : The upper petal of a papilionaceous flower; the standard.

Vexillum n. : The rhachis and web of a feather taken together; the vane.

Example:
If Rome had a national flag (Vexillum) what would it look like?

Taxonomy
vexillum, flags, free encyclopedia, Emperor Tiberius, sail, cloth, Rome, Cisalpina, Vexilla Regis, search, re-enactor, scorpion, the sign, honor, the Emperor, Praetorian Camp, Photo, Associazione Culturale.

Defination from the web:
vexillum with a scorpion, the sign of the Praetorians which was used to honor the Emperor Tiberius for building the ... The vexillum (plural vexilla) was a flag-like object used in the Classical Era of the Roman Empire. ...