App for note-taking and marking up PDFs. I can just "write" on a piece of lined virtual paper, draw on a blank slate, mark-up contracts, highlight legislation we're reviewing in class, etc.
I use my tablet computer (chromebook) for tabletop.
Google Keep to keep track of various games, using tags to separate and group them. Every campaign has a note for characters, a note for locations, and a note for quests. The game I run has session plans, all titled for quick reference.
In addition, I use Squid along with a stylus for jotting down notes while the game is going on. This is great for keeping track of combat, initiative, etc, as well as little things like what those unidentified potions are, and where the players are most likely to go during the next session. All of this eventually gets built into Keep after the game has ended.
Squid is also great for explaining room/hallway layouts since you can set it to a grid background.
Have you seen the Squid video? If you're willing to use Squid, it seems they had a special partnership with Google to get the lag way down. Worth looking into and you can try the app now (minus the pen) to see if it does what you want.
The video will pop up once you visit the site (give it a second): https://www.squidnotes.com/
You can use Squid Notes, which is not technically what you're looking for, but you can take notes of your new words quickly with it, without being bothered with things like fonts or difficult diacritics input. And then you can update your master list when you go back home or have some spare time.