. . . xiphoid process!
Let me explain.
One of Zahana's favorite things to do is to name body parts. When I grew tired of hearing "eyes, nose, mouth" over and over again, we branched out to chin, elbow, toe. . . until finally I said, "Hey, just for kicks, let's learn something a little unconventional!" And so I showed her xiphoid.
A couple days after I showed her, she came to me with her arms crossed over her chest and said, "Where diboy?"
There it is! Yay!