Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
the rate at which something happens:
the falling or hitting of an object or beam of energy, such as light, on a surface
Share your knowledge with the community
Browse our collection of 300,000+ community-written definitions