This app is not only dictionary, but also word list and translator.
Moreover we can use it very easily.

When you see the word which is unknown, you just copy that word.
Then meaning of word is displayed on your screen.

And that word resistered in your word list, and linked to web dictionary.

This app is FREE.
https://play.google.com/store/apps/details?id=com.myclips

I recommand this app to you.