What is the Jewish/Hebrew term for when you "kill" someone with words, as opposed to a physical act?

This was brought up in a class recently, and I cannot for the life of me remember the terminology used. The tutor said to us that to speak (unjustly) ill of someone is, per Jewish teaching, as bad as physically harming or even murdering someone – as to damage their reputation is akin to killing a part of their soul.

I have tried to search for the term this describes, and even asked an Orthodox Rabbi who is usually able to help me with these kind of queries – but even he is unsure in this case.

The tutor I learned this from was an Orthodox Jewish woman, who was generally very knowledgeable about the subjects she teaches, so I am pretty sure her source of this info was legitimate. I just can’t seem to find it again, and am hoping someone here knows what I am talking about!

Thanks 😊