Means custom, in that context. Ah, that makes sense, and there is one less thing poking at my brain. *sigh of contentment*
Also learned a new word for a 3-dimensional trapezoid, or the bit that's left over after you truncate something: frustum. (Before you math people start pulling your hair out at my lackadasical definition, a formal one is behind the link.)
That plus moissanite, and I've collected more words in the last couple of weeks than I have in some time.
Of course, you have to understand the rules - just browsing the dictionary doesn't count, you have to encounter them "in the wild" or by wondering what something is - in other words, it doesn't count as collecting unless you come upon it in a fashion unrelated to the collecting process. It doesn't count to simply go "I'm going to look up five new words today" or something like that. Things looked up from technical articles don't usually count either, because if a definition can be gleaned from context it doesn't really count as new. Plus technical language is specialized, and I'm more interested in collecting day-to-day words that I don't know.
Hey, it's my game so it can have bizarre rules if I want it to. Besides, I think this is the first time I've bothered to try to articulate the rules outside of my own head, so you're lucky they are as coherent as they are...