It would, but depending on the dictionary there might not be much, if any, context about the game.
You could get a simple “Concker(n), colloquial name for the seeds of the horse chestnut tree” or “Conckers(n), traditional game played mainly in the British Isles with seeds of the horse chestnut tree” – a concise definition of the what without any detail of the game or its cultural significance (it was a big thing for a short time each year back when I was of school age, and had been for generations).
“when I was very young and read the Hitchhikers Guide for the first time” suggests this was quite some time ago, so further lookups might have required a physical trip to a library, rather than just clicking a link or throwing a term at an online search engine.
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.
You could get a simple “Concker(n), colloquial name for the seeds of the horse chestnut tree” or “Conckers(n), traditional game played mainly in the British Isles with seeds of the horse chestnut tree” – a concise definition of the what without any detail of the game or its cultural significance (it was a big thing for a short time each year back when I was of school age, and had been for generations).
“when I was very young and read the Hitchhikers Guide for the first time” suggests this was quite some time ago, so further lookups might have required a physical trip to a library, rather than just clicking a link or throwing a term at an online search engine.