snowball effect [snoh-bawl-ih-fekt]
noun
1. a process that starts from an initial state of small significance and builds upon itself, becoming bigger, more dangerous, etc.
EX. First, you throw a snowball. Then, he will growl at you. If you throw another, he will show his teeth. And if you throw a third snowball, he will maul you.
That is the snowball effect.
