She knew from a young age that her sole 'purpose' (in life) was to be a writer. [=she knew that all she wanted (in life) was to be a writer]
We were happy to know that the money was being used 'for a good purpose'. [=for something useful, important, etc.]
There's little/no 'purpose' in restarting the process. [=there is little/no reason to start the process again]
(..) sail away with my ship. But you were marooned on this island before. We can escape the same way you did. To what point and purpose, young missy? The Black Pearl is gone. Unless you have a rudder and sails hidden in that bodice. Unlikely. (..)2003 Pirates of the Caribbean: The Curse of the Black Pearl
(..) It's such a pretty boat. Ship. What's your name? Smith. Or Smithy, if you like. What's your purpose in Port Royal, Mr.Smith? Yeah. And no lies. Well, then, I confess. It is my intention to (..)2003 Pirates of the Caribbean: The Curse of the Black Pearl