OK, so it's not actually a book anymore.
I started collecting names and their meanings about the same time I started dancing, back in the dark ages when we still had rotary phones and slide rulers. Hasani's Awesome Book of Names was originally an ever-expanding set of 3-ring binders in which I collected names, along with their language of origin, meaning, and variations. The notebooks have now become a database, but I still refer to it as my "Book of Names".
38,000 names and counting!
A little transparency here - the database thinks each name variation is a new, separate name. The number 38,000 is artificially high, but it's the only number the software will give me. I would put Ann, Anne, and Annie in the same category, but the database doesn't. How many names are there without the variations? Honestly, I have no idea.
I'm not any sort of authority on the subject.
The names were collected over the span of 40-something years, and were sourced from whatever books and lists I could find. I didn't make note of my sources along the way. This was just for me, and just for fun, which means now that I'm sharing my collection, I have no sources to cite.
It doesn't work like a dictionary, folks.
"Language of origin" is not the same as a direct translation. An example: the name Ashley has English origins and means "from the meadow of ash trees", but that doesn't mean present-day English speakers call a grove of ash trees an "ashley". If you're hoping to translate the name of your new business into another language, my Book of Names is not your best option.
They're all actual names.
These are names parents have actually been giving their babies. Sometimes people are looking for very specific meanings that...well...just aren't the sort of thing people name their kids. My list won't be much help if you're looking for a name that means "rainbow unicorn", "sassy butt", or "seducer of Klingons". Yes, those were actual name search requests I've received. Nevertheless, there are a few names with highly unusual meanings. They're good for a giggle, and you just may find your next role-playing name there.
Most names have simple meanings.
The simpler the keywords, the better. (Miwok names are a glorious exception) Individual words like "beautiful", "princess", "golden", or "moon" will yield lots of hits, while complex searches like "beautiful princess of the golden moon" will probably come up empty.
If all else fails...
...an online word translator can be your friend! There are a ton of them on this list. There's also Google Translator, but just be aware the results can be, ah, interesting.
Case in point: I ran the lyrics to a Finnish folk song through Google Translate and it came back with "Why do the maidens water bears?" I have no idea why maidens would be watering bears, but it all made sense when I eventually found a better translation - "Why do the maidens bear (carry) water?" It was a whole different song now that nobody was watering bears anymore.