My Current Favorite Digital Dictionary - Google Dictionary

Over the years, I've relied on digital dictionaries like WordWeb which is great as a desktop app and the hip & modern Vocabulary.com to look up meanings or the right words.

Of late, I've been using and finding the Google online dictionary service through the "define" operator very useful as it provides:

• pronunciation aids: audio in different accents (British, American and sometimes Indian English), "non-phonemic pronunciation respelling" which literally "respell" words making use of well-known English words and spelling conventions instead of using formal phonetic transcriptions.
• word origin chart: helps in knowing a little about the background of the word to better remember and pronounce it. I was pleasantly suprised to know that the word "cushy" is derived from the Urdu word kushi and it now makes sense why it is pronounced as such.
• a chart showing the word's popularity or usage over time 

Google licenses English dictionary data from Oxford Dictionaries.