Oxford English Dictionary - OED (for Bluedict and Mdict)

The Oxford English Dictionary (OED) is the accepted authority on the English language, providing an unsurpassed guide to the meaning, history, and pronunciation of more than 280,000 entries – past and present – from across the English-speaking world.

The OED is a historical dictionary and very different from dictionaries of current English where the focus is on present-day meanings. It contains the history of each word, and of the language, traced through more than 3.5 million quotations, from classic literature and specialist periodicals to film scripts and cookery books.

Just like many other third-party apps, BlueDict is only a database "reader". So you need to get the databases (.MDX .MDD .CSS) then put them into /sdcard/BlueDict/Dicts or your specified path.