Terminology has always had great direct integration with our own apps, Drafts and Phraseology that allows you to easily lookup and select replacement words and have them directly replaced inline with your editing. You can see that integration in action.
In the latest version (3.0.6) of Terminology, I added a tweak to its URL schemes to allow it to integrate more easily with certain other apps, particularly Editorial, Ole Moritz’s excellent iPad text editor.
Terminology is my favorite dictionary app and I wish Editorial had a popover to replace Apple’s default dictionary, like Instapaper did. The workflows are the best alternative to that for now, and they work well.
It would be nice to have selectable synonyms and antonyms built into the system dictionary in iOS 8.