What does ta shun mean?

"Ta shun" is not a recognized word in any major language. It's possible that:

* It's a misspelling. Perhaps you meant a similar-sounding word like "ta-shun" or "ta-shan"?

* It's a specific term within a particular field or context. If you can provide more information about where you encountered the term, I might be able to help you understand its meaning.