What's that mommy/daddy?

Recently I was reading a submission by Puma called Legend. In it he tries to describe what an abyss is to a little boy.
I thought that that might be an interesting game that could be used as a good writing exercise.

Basically you have to try and get into the mind of a four and five year old and try and describe a word or phrase. Once you’ve described it, or tried, J you then leave a word or phrase for some else to describe. You can take it as a serious exercise or have fun with it. Just keep it PG. Try to keep it short. Make it 10 short lines or a paragraph. (I’ve gone a bit long on mine.)

I’ll go first: What’s a helicopter?
Boy - What’s a helicopter?
Dad – Well it has a blade on top that spins.
Boy – A blade? Like a knife?
Dad – No. You remember the beanie hats with that little spinning thing on top?
Boy – Yes.
Dad – Well imagine that on an airplane.
Boy- One of those little spinny things on a big plane?
Dad-Well the helicopter is much smaller.
Boy-How small? Holding his hands a foot apart.
Dad-Like about the size of your playset.
Boy-Why would you put a beanie on a playset?

Describe a Vacuum in Space

Good. Now give me your word and please don't make it antidisestablishmentarianism, 'cause I don't even know what that means.

Girl - What's a typewriter?
Dad - Well, you know this thing that daddy types on all day?
Girl - It's a keyboard. I know what a keyboard is.
Dad - . . . O-Ok. He leans the keyboard against the monitor. Imagine this keyboard on top of a machine. You feed a paper like this into a . . .
Girl - Does it eat the paper?
Dad - No. You . . . put this paper through a little roller at the top. Then, when you type something a little lever flies out and prints whatever you press. Kind of like magic. Then when you're all done the paper comes out the back.
Girl- Looks behind the keyboard dubiously. Can I try that daddy? She seizes the paper and looks for a place to feed the paper.
Dad - He lays the keyboard flat on the desk. No. It's a keyboard. Not a typewriter.
Girl- Oh. Somewhat mistrustfully


What's a lawn mower?