1. A waterfall, or several waterfalls, that go over rocks: The tourists enjoyed watching the cascades of the stream flowing over the stones.
2. A big amount of something that hangs down: Marge had a cascade of blond hair falling down her back.
3. Something that falls in a progressive manner or in aa series of fast steps: The decision of the government officials set off a cascade of negative responses by the general public.

Jason watched as the religious pilgrims climbed up the cascade of stairs on their knees to the cathedral.

1. To flow down or to hang down in large quantities: When Lina heard that her sister died, her tears cascaded down her cheeks.

Helena's dark hair cascaded down her back all the way to her waist.

2. To move on to others through the years: The poverty of past generations of the country has cascaded down into the present offspring.

1. A chain reaction that starts when one free electron collides with one or more orbiting electrons and frees them.

The free electrons then free others in the same manner, etc.

2. The cumulative process in which an electron (or other charged particle) accelerated by a strong electric field collides with and ionizes gas molecules, thereby releasing new electrons which in turn have more collisions, so that the discharge is self-maintained.