mole

/moʊl/
noun
  1. A small animal with dark fur, a pointed nose, and very small eyes that lives mostly underground and digs tunnels.
    • The mole uses its strong front claws to push dirt out of the way.
    • Because moles are nearly blind, they rely on touch and smell to find food.
    • A mole dug a tunnel across our backyard last night.
  2. A person who works secretly inside an organization to gather information for another group, such as a government or company.
    • The spy agency discovered a mole in their own headquarters.
    • The company fired an employee who was acting as a mole for a competitor.
    • In the movie, the hero must find the mole before the secret plan is revealed.
  3. A small, dark, raised spot on a person's skin, often present from birth or appearing over time.
    • He used sunscreen to protect the mole on his shoulder from the sun.
    • You should see a doctor if a mole changes shape or color.
    • She has a small mole on her left cheek.
  4. A unit of measurement used in chemistry to represent a specific number of atoms or molecules (about 6.02 × 10²³).
    • One mole of water contains about 6.02 × 10²³ molecules.
    • Students learn how to convert grams to moles in chemistry class.
    • The chemist measured out one mole of sodium chloride for the experiment.
  5. A thick, spicy sauce made from chili peppers, chocolate, and other ingredients, originally from Mexico.
    • She spent hours preparing the mole from scratch using dried chilies and spices.
    • Mole poblano is a traditional dish often served at celebrations.
    • We ordered chicken with mole sauce at the Mexican restaurant.