Here's a practical source where you can quickly enter a word, and a definition, example sentence, and long list of synonyms and similar words appear. Additionally, there appear to be possibly many literary references for each word. Enter pariah, for example, and you'll see the word's use by writers such as Twain and Kipling. The site doesn't offer anything on etymology that I've come across in a few minutes of browsing.

My apologies in advance if this site is for primarily commercial purposes.

http://www.thefreedictionary.com

Edit: Well, there are advertisements here and links to sales, but those are easily avoided if your mouse finger's under control.