[vek'silә]
[植]旗瓣, 羽瓣

Vexillum \Vex*il"lum\, n.; pl. {Vexilla}. [L., a standard, a
flag.]
1. (Rom. Antiq.)
(a) A flag or standard.
(b) A company of troops serving under one standard.

2. (Eccl.)
(a) A banner.
(b) 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.