Currently the look-up works for me, though not without hiccup. One caveat is that instead of a less intrusive pop-up (like you would get from looking up a word in a webpage/pdf/whatnot) - in obsidian - the entire dictionary app fires up. Depending on whether a word is selected, one of the two below happens:
If the word is not selected (i.e. directly 3-finger tapping on a word), chances are that the dictionary app doesn’t look up the word. It just opens and does nothing.
If a word is selected, then the dictionary app still pop-up, but it now captures the word and automatically paste it into the search bar.
Personally, I’d prefer the less-intrusive pop-up (built-in). But if the dictionary app has to be fired up, then I guess I still want the lookup be performed in cases where the word is not a priori selected.
This in the number one thing I find myself missing from obsidian at the moment. Even though it may seem small, right clicking a word and hitting Look Up from the context menu is something I do all the time.
It’s a shame obsidian prevents this. It means I have to copy the word and paste it into spotlight and then look-up from there. Lots of extra friction in what is very fast and easy in most other apps.