from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A gradually spreading effect or influence: "Those deviations tend to have a ripple effect throughout the economy as a whole” ( Tom Clancy).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the effect of one event setting off other events in an unexpected way, or unexpected areas.
by analogy with the spreading ripples on the surface of a body of water when a stone is thrown in. (Wiktionary)