Kudos Wiktionary Word of the day APP and WIDGET.

Learn a new word everday by either launching the app or including a widget on your home screen (To add a widget after installing the app tap on an empty part of your background and select 'widgets' then 'Wiktionary')
Tapping the widget will give a full explanation of the word.

Dictionary data taken from wiktionary.com
Parts of the source are taken from or modified versions of that found on the Android Developer Blog.

Offline English-Basque and Basque-English Dictionary. More than 9.000 words. FREE!

Offline English-Polish dictionary. Angielsko-Polski Słownik.
More than 60.000 words. FREE!

Expand your English vocabulary and gain eloquence and quick-wittedness!

Expand your German vocabulary and gain eloquence and quick-wittedness!

Offline Spanish German dictionary. Spanisch Deutsch Wörterbuch Diccionario español-alemán
More than 42.000 words! FREE!

Offline English Slovak dictionary. Anglicko-slovenský slovník.
More than 100.000 words. FREE!

Offline English Czech dictionary. Anglicko-český slovník.
More than 164.000 words. FREE!

English-Croatian and Croatian-English Offline Dictionary.
Englesko-Hrvatski i Hrvatsko-Engleski Offline Rječnik.
More than 120.000 words. FREE!

Offline English German Dictionary. Englisch-Deutsch Wörterbuch.
More than 168.000 words. FREE!

Offline English Hungarian Dictionary. Angol Magyar Szótár offline.
More than 235.000 words. FREE!

Offline English-Norwegian dictionary. Engelsk-Norsk Ordbok offline.
More than 29.000 words. FREE!

The only offline English-Catalan dictionary for Android. More than 33.000 words!

Offline English Finnish dictionary. Englanti-Suomi sanakirja.
More than 63.000 words. FREE!

Offline German-Dutch Dictionary. Duits-Nederlands Woordenboek. Deutsch-Niederländisch Wörterbuch.
More than 49.000 words! FREE!

Offline German-Swedish Dictionary. Tysk-Svensk Ordbok. Deutsch-Schwedisch Wörterbuch.
More than 14.700 words! FREE!

Offline English Swedish dictionary. Engelsk-Svensk ordbok.
More th 35.000 words. FREE!

Offline Spanish Swedish dictionary. Diccionario Español-Sueco. Spansk-Svensk ordbok.
More than 22.700 words. FREE!

Geiriadur Saesneg-Cymraeg a Cymraeg-Saesneg.
The only Offline English-Welsh Dictionary for Android! More than 14.900 words! FREE!

Offline English Japanese Dictionary. Over 210.000 words and expressions!
英和辞書 offline。単語、成句、熟語を21万!
FREE!