I chose "quench" as a medium difficulty word because:
1. It's 6 letters long, fitting within the rules
2. It contains the uncommon letter 'q' which makes it challenging
3. But it also has common letters like 'n' and 'e' to give the player a fair chance
4. It's a real English word meaning "to satisfy thirst" or "to extinguish"
5. It doesn't contain any special characters, spaces, or hyphens
6. It's not a proper noun or acronym