This was actually before I started elementary school. Once I did start school I recall looking it up and not finding anything in the dictionaries to which I had access in a midwestern small town - school, local public library etc. I assume if I had checked the big pedestal dictionary in the public library I would have found it. But being very young I didn't think to. When I reread it a few years later (still very young) I just got the context that it was a kids game and moved on. I wasn't ever so desperate to know that I went avidly looking for an answer. But when my aunt went to London I did think to ask so I got an answer.