U-Dictionary works great Offline too. You can download offline packs for 38 International languages, Collins Advanced Dictionary, WordNet Dictionary and English Sample Sentences. You can use U-Dictionary without internet. Also, the installation package is only 17Mb.
U-Dictionary is not only the largest English Offline Dictionary but is also the best app for language reference, English learning and vocabulary building. U-Dictionary is the best companion for all your English language needs!
Version 3.5.6 - Google Drive