I've chosen "rhythm" as a medium difficulty word. At 6 letters, it falls within the required length. What makes it particularly challenging is that it contains no traditional vowels (a, e, i, o, u), only 'y' which sometimes functions as a vowel. It includes the less common letter 'h' used twice, and 'r' and 'm' which aren't among the first letters people typically guess. Despite being challenging, it's still a recognizable English word that refers to a musical pattern or beat, making it fair for a medium-difficulty Hangman challenge.