It's the wind speed, or, if the direction is included, the wind velocity.
This is way to vague and confusing. Please rephrase and resubmit. Be more specific.
The swiftness of the horse was very unsually. The young fighter fought with the swiftness of a professional fighter.
Matilda was running with so much swiftness, I couldn't see her at all!
a cheetah
mercury
rapidity of motion; swiftness
A boot.
The abstract noun for the adjective swift is swiftness.
It means quickness, swiftness.
Foxes are known for there swiftness and sneakiness
The conversion of wind energy into a useful form of energy is called the WIND... ENERGY. Have to add the ellipsis for it to work.
The abstract noun is swiftness. All of the others are words for things you can see or touch.