Yeah, some of the terms aren't clearly defined. I had to dig around a lot to satisfy my curiosity. These are the technical details to expand on what the others mentioned:
True Dungeon - The actual name of the game. But also means a dungeon or adventure run. A dungeon run is typically seven rooms played over 2.25 hours and may be either combat or puzzle oriented, but will always contain aspects of both. There are no XP rewards or buttons for WYC and just one rare completion token across difficulties, at least for 2015. Treasure draws for WYC are as usual.
There are several difficulty levels:
Non-lethal Dungeon - Nobody can die. 650 XP. Normal completion token. Treasure draws.
Normal Dungeon - 650 XP + 50 XP/room reached. Normal completion token. Treasure draws. Normal survivor button.
Hardcore Dungeon - 1650 XP + 50 XP/room reached. Hardcore completion token. Treasure draws. Hardcore survivor button.
Nightmare Dungeon - 1650 XP + 50 XP/room reached. Both the Normal and Hardcore completion tokens. Treasure draws. Nightmare survivor button
True Grind - A specific type of adventure that is a gauntlet run of various monsters. I.e., just combat.
You can only participate in a grind adventure if you have reached 2nd level as a player.
There are several difficulty levels for a Grind run, but the rewards are the same.
Normal, Hardcore, or Nightmare Grind - Grind completion token. One treasure draw. Grind survivor button.
Treasure Draws - You get to pull a token out of a box. You get one treasure draw for completing an adventure. (Getting to the last room, but not necessarily surviving it.) There should be NO common tokens in the box. It should be mostly uncommon and rare tokens. But 1% can be truly epic and just about anything in or out of circulation, so the more draws you get the better chances of getting great loot!
Treasure Rooms - In the dungeon runs there will be three treasure rooms (they have a big T on the wall). You need to solve the puzzle or defeat the monster to get the bonus for that room.
These items affect treasure at the end of dungeon runs (and because of that, they tend to be pricey):
Amulet of Treasure Finding - A.k.a. AoTF. Awards four bonus treasure draws upon adventure completion when worn (neck slot).
Charm of Avarice - A.k.a. CoA. Combines the rewards of HoP, RoR, and CoGF upon adventure completion when worn. Counts as a CoGF for the purposes of determining the CoGF reward level. Mutually Exclusive with all of the other bonus treasure items.
Charm of Good Fortune - A.k.a. CoGF. Awards two, three, or four bonus treasure draws upon adventure completion when worn. Actual number depends on the number of players carrying a CoGF (or CoA).
Horn of Plenty - A.k.a. HoP. Changed for 2015. Awards six bonus treasure draws upon adventure completion when worn (neck slot).
Lenses of Fortune - A.k.a. LoF. Awards one bonus treasure draw upon adventure completion when worn (eye slot). Mutually exclusive with all of the other bonus treasure items.
Ring of Riches - A.k.a. RoR. Awards three bonus treasure draws upon adventure completion when worn.
This is my understanding at present. The details shift year-to-year. I may be wrong.
OK, this got out of hand. Hope it helps.
Thanks!
Lode