Mule
Part of speech: noun
Definition: A generally sterile hybrid offspring of a male donkey and a female horse. A generally sterile hybrid offspring of any two species of animals. A stubborn person. A person paid to smuggle drugs. A woman's shoe that has no fitting or strap around the heel
Example sentence: As the facts change, change your thesis. Don't be a stubborn mule, or you'll get killed.
Scuff
Part of speech: verb
Definition: To mishit (a shot on a ball) due to poor contact with the ball.To scrape the feet while walking.
Part of speech: adjective
Definition: Caused by scraping, usually with one's feet.