Yesterday, we were having lunch and I mentioned getting a tripod for the Galileoscopes I'd gotten the kids for Hanukamas.

Son the Elder: What's a tripod?

DH (getting all teachable-momenty): Well, do you know what 'pod' means? It means foot. And 'tri' means?

StE: Three.

DH: So what do you think tripod means?

StE: A yard! Because three feet make a yard.

And then we all dissolved helplessly into giggles.