What are good words for a word guessing game?

It is a game where you need spelling and yes or no questions so I need hard words or words that have common beginnings. No proper nounsWhat are good words for a word guessing game?The only word that defeated me in a spelling bee was "disingenuous". So that might be a good one! I was about 12 or 13 years old. Wish you had included age range of participants.