Oh, well, a mamil is a word that some people use to describe men who really like to ride bicycles. They wear tight clothes like superheroes and have special shoes that clip into special pedals. They even have special helmets that make them look like cool astronauts!
Sometimes, these men ride really fast and really far on their bikes, even though it makes their legs feel tired. They think it's lots of fun and important for staying healthy. Just like how you ride your bike with training wheels now, when you grow up you might become a mamil too!