What's the Context?

Want to know the bad part about letting your kids be readers?

Wait, wait, wait. Don't freak out on me yet. I'm not going to quit letting my kids read because it's not really a bad thing. But I got your attention, didn't I?

So, for real, here's what my problem is. My eight-year-old lately out of nowhere asks me "What does this word mean?" And words I have known forever suddenly are undefinable. Their meaning slips out of my head just like that. *snap*

A lot of times I don't lose the meaning because I can't remember it. It's more a question of how do I define this word in terms he understands? So, I send back the question, "What's the context?" Where did he read the word? Was it in a book? On a billboard? In a song? Where is the question coming from?

The first few times I asked, he wasn't sure what I was wanting to know, but now we're in a routine and he can usually either read the line or explain the situation so I can get a grasp of where the word is coming from. Which lets me help break it down where he can understand it as it's being used there.

Of course, words can change their meaning depending on how they're being used, but that's a lesson for another day. 

Needless to say, he's not only improving his vocabulary by reading, but he's also stretching my ability to remember what words mean. Which, when driving through crazy school traffic early in the morning, isn't always easy. 

What's something you've run into that's a "problem" with letting kids read? Got any tips for remembering how to define a word to an eight-year-old?