Koichi over at Tofugu just wrote an article about Why you should use a Mac to study Japanese, but I think the built-in dictionary is definitely one of the best resources on the Mac for Japanese. I had my MacBook for approximately two years before I even realized there was such a dictionary (would have been really helpful to know about during the year I lived in Japan and had my MacBook!) and it seems a lot of people I’ve talked to also don’t know about the Japanese dictionary.

The reason it’s a “secret” is that the Japanese dictionary doesn’t automatically show up as part of the Dictionary app. You’ll need to open the preferences, and then voila, you’ve discovered a gold mine:

So just select to enable the Japanese-English and Japanese dictionaries, and you’re ready to go! (There’s also a Japanese synonym dictionary which I haven’t used too much, honestly)

If you’re familiar with inputting Japanese text on OSX, the dictionary is very easy and nice to use. Here’s an example looking up the Japanese word びっくり (bikkuri). Type the word (Dictionary will auto-complete the word for you as you’re doing this):

Click for a definition, some synonyms, and example sentences:

The dictionary gives you a very standard-Japanese definition (not a lot of slang or new words) but it’s very solid and extremely helpful.

English-Japanese isn’t bad either:

And once your Japanese is coming along, you’ll want to start using the Japanese-Japanese dictionary as well. This dictionary is more extensive than the Japanese-English dictionary, so especially with proper nouns, old words that aren’t used much anymore, or more technical/specific/historical vocabulary, it may only be in the Japanese dictionary. Here’s what a Japanese dictionary entry looks like:

This dictionary isn’t perfect, but since it’s a desktop app that doesn’t rely on an internet connection, it’s been extremely useful. I generally use it as my primary dictionary, and then seek other resources if I need them (like jisho.org for kanji-lookup, for example). I also used the Dictionary app during exams for my Japanese translation class this semester — we were allowed to have dictionaries, but no internet connection (I suppose so we wouldn’t chatting with other people taking the exam, or something like that).

As a Mac user/Japanese learner I’m excited about the cool new things Koichi mentioned, like the new Chinese input method that will come out with Snow Leopard, but I just wanted to make sure you don’t miss the built-in dictionary like I did!