How is feature testing different from functionality testing?

This is where good communication skills, alertness and good vocab comes in handy for a tester....

Looking at the meanings of the terms in question, Feature testing: a distinctive attribute or aspect of something. Functionality testing: the quality of being suited to serve a purpose well; practicality. So with the knowledge of the meanings of these terms you can come up with a good enough explanation spontaneously. As it is there are many terminologies made by people in testing. And to different people and organisations a term may have a different meaning. So it is always better to give an appropriate explanation depending on the context....