The app should send events that measure user engagement with the new Wiktionary definition dialog.
Here's the schema: https://meta.wikimedia.org/wiki/Schema:MobileWikiAppWiktionaryPopup

I was thinking that we could send just one event, when the dialog is closed. (Since the dialog is modal, a "close" event implies that it had already been "opened" previously. The "close" event contains the amount of time that the dialog remained on the screen, as well as the actual text that was highlighted)