A sterile person can't have kids, and a sterile environment is bland and boring. In both cases, sterile means lifeless.
When you hear about a sterile person, it means they can't have kids: sterile women can't get pregnant, and sterile men can't be fathers. But the concept of sterility applies to things, too. An empty, white room with nothing in it is sterile. And a surgeon's instruments better be sterile — meaning they're free from germs and bacteria.
