At the moment, Thesaurus App is not available for direct download on a computer. However, you can use emulators to run it on PC. The downside is that using Thesaurus App with an emulator might slow down your computer's performance.
Learn how to use Thesaurus App on your computer in these 5 simple steps:
Retrieve the synonym for every word. If available you will get antonyms, related terms, similar word and user suggestions too. Tap one of the results to start a quick new search for that term. It keeps a history list of your search terms as well. Runs on the Apple Watch and supports the iPad multitasking mode (split-view) on iOS9.