Originally Posted by Doitsu
AFAIK, the word lookup only works with languages that use the Latin alphabet.
It appears that the Duokan developers are working on versions for K4s. They released a K4NT version this week and I wouldn't be surprised if they followed up with versions for other Kindles.
Resources For Kindle – Kindle 资源收集
offers free Chinese-English dictionaries for download, but I don't know if they work on the Kindle Touch.
Of the 3 Chinese-English dictionaries linked, 2 are actually English-Chinese dictionaries, and the third link didn't work for me. I ended up creating my own CC-CEDICT dictionary in mobi format (In case anyone is interested, I just created a mobi for CC-CEDICT (see attachment). It's been working very well for me on a Paperwhite (on stock Kindle software--no Duokan needed).
The OP should be updated, as Chinese dictionaries DO work without Duokan (at least on the Paperwhite, I can't speak for the other models).