I've realized that I've been foolishly missing another point of immersion that is available in multiple languages - Wikipedia. Indeed I've been able to find what I needed in Polish quite easily (fortunately my search term has Latin roots)... But not in Welsh, as far as I can tell. And in fact by the number of articles Welsh Wikipedia is below Volapuk, an invented language, and Irish is even worse... The problem is that obviously I'm not the only one who finds those languages inexplicably charming. It seems that a lot of fantasy writers tend to derive their languages and cultures from there, among them Andrzej Sapkowski, whom I'm reading right now... Sigh.