Rapidity (noun)

1. The state or quality of being rapid; swiftness, speed.
2. The rate at which something happens or changes.
3. A quick succession of movements or events.

Origin:

From latin rapiditatem, accusative of rapiditas, from rapidus ("swift, quick, fas.t")

Examples:

1. The rapidity of the river's current made it difficult for the swimmers.
2. The company's success was due to its rapidity in adopting new technology.
3. The rapidity of the conversation made it hard for me to keep up.
4. The rapidity of the storm's approach caught everyone off guard.
5. He was impressed by the rapidity of the worker's movements.