I don't know from when(maybe after upgrade to Catalina), Mac's three finger tap option begins to show results from such as Siri Wikipedia or App Store instead of dictionary definition. And there's no setting for changing this.
MacBook
All of those should be showing up, along with he Dictionary definition. You can swipe across to view the different types of information.
I don't know why yours is not showing the Dictionary. As you noted, there are no settings, so I don't know how to reset it.
If you ctrl-click and choose Look Up, does it show the Dictionary? Its the same feature, so I wouldn't expect it to be different.
You didn't need to post a picture (twice). We understand you don't see the Dictionary entries.
However, I don't know how to go about fixing it.
Maybe try booting into Safe Mode, then restart normally. It will clear some system caches which might help.
Use safe mode to isolate issues with your Mac - Apple Support
As you can see, there's no dictionary anymore
it no longer shows dictionary as you can see
Now after few days it turns out working again. Don't know what happens but appreciate your helps anyway.
It is still working here on Catalina:
Why the three-finger-tap function now no longer shows definition for words?
