QuickDic Dictionary

Uses data from Wiktionary to generate dictionary files that can be used offline. These can be downloaded from within the app. Both translation and single-language dictionaries available.
Use the long-press menu of a word to have your device's text-to-speech implementation speak it for you (you may need to install text-to-speech data for the language first).

If you experience app crashes I can generally see, investigate and often fix them. But if they do not get fixed I likely do not have enough information to do that, and reporting them (and other issues) on github (https://github.com/rdoeffinger/Dictionary/issues) would likely be helpful.
Note: I am not the original author, but I took over maintenance of the original QuickDic app.

Source code is available here: https://github.com/rdoeffinger/Dictionary but little documentation (in the readme.txt) so far.

The adventurous can choose to get the beta version here if you want to follow development more closely: https://play.google.com/apps/testing/de.reimardoeffinger.quickdic