1. To depart. I better get going so I don't miss the train. Come on, kids, let's get going—the party starts in 20 minutes. Get going or you'll be late!

2. To cause someone to start enthusiastically discussing some topic. In this usage, a noun or pronoun is used between "get" and "going." Don't get Grandpa going about the weather unless you want to hear about the Farmers' Almanac all night.

3. To start taking some action. We need to get going if we want to get this house cleaned up before your mother gets here.