What is "vexillum"

Vexillum \Vex*il"lum\, n.; pl. Vexilla. [L., a standard, a flag.]

1. (Rom. Antiq.)

   1. A flag or standard.

   2. A company of troops serving under one standard.

2. (Eccl.)

   1. A banner.

   2. The sign of the cross.

3. (Bot.) The upper petal of a papilionaceous flower; the standard.

4. (Zo["o]l.) The rhachis and web of a feather taken together; the vane.

n. 1 A flag, banner, or standard. 2 A company of troops serving under one standard. 3 The sign of the cross. 4 (context botany English) The upper petal of a papilionaceous flower. 5 (context zoology English) The rhachis and web of a feather taken together; the vane.

The vexillum (; plural vexilla) was a flag-like object used as a military standard by units in the Ancient Roman army.

Vexillum is a genus of small to medium-sized sea snails, marine gastropod mollusks in the family Costellariidae.