Slime is a thick, slippery, gooey substance. A slug leaves a trail of slime as it crawls. Pond algae feels slimy when you touch it. The word captures that gross, sticky, wet feeling of something that makes you want to wash your hands.

In nature, slime often has a purpose. Snails and slugs use their slime to glide smoothly over rough surfaces. Hagfish produce clouds of slime to escape predators. Even your own body makes slime: mucus in your nose and throat is a type of slime that helps trap dust and germs.

Kids today also know slime as a popular toy made from glue, borax, and water. Homemade slime stretches, squishes, and makes satisfying sounds when you poke it. While toy slime is fun to play with, the word itself usually suggests something unpleasant or unwanted.

When something is slimy, it's coated with or feels like slime. A rock covered in algae is slimy. The word can also describe a person who acts fake or manipulative, like a slimy character in a story who pretends to be your friend but secretly wants something from you. That kind of sliminess refers to behavior that feels dishonest and makes people uncomfortable, just like actual slime can make your hands feel gross.