Dandle is a verb that means to bounce on one’s knees or in one’s arms. 

The exact origin of our word of the day is unknown, but we know it’s been with us since the mid 16th century and it has a very specific use, meaning it should not be used to refer to bouncing anything on one’s knee except a baby. Here’s an example of dandle in use:

I would say it was somewhere around their fiftieth birthday that it was no longer a good idea to dandle my kids on my knee. Not only were they getting bigger by then, but my knees were getting far too tender for such wear and tear.