Definition

1. Noun:

   • A hard outer layer or covering: A firm, often brittle, exterior surface that forms on something, especially through drying, cooling, or baking.
   • The outer layer of the Earth: The solid, rocky outermost shell of the Earth, lying above the mantle.
   • Rudeness, impertinence: (Informal) The trait of being insolent, disrespectful, or taking undue liberties.

2. Verb:

   • To form or become covered with a hard outer layer: To develop a crust on the surface.

Examples of Usage

• Noun:

  • The crust of the bread was perfectly golden and crisp.
  • Earthquakes originate in the Earth's crust.
  • He had the crust to ask for a raise on his first day. (Informal)

• Verb:

  • The mud had crusted over in the summer heat.
  • The sauce will crust if you leave it uncovered.

Advanced Usage

• "The upper crust": (Idiomatic) The highest social class; the aristocracy or the very wealthy.

  • The exclusive club was frequented only by the upper crust of society.

• "To earn one's crust": (Idiomatic, chiefly British) To earn one's living; to make enough money for basic necessities.

  • He's been earning his crust as a freelance writer for years.

Variants and Related Words

• Crusty (adjective):

  • Having a hard crust.

    • A crusty loaf of bread.
  • (Of a person) Irritable or curt.

    • The old sailor was a bit crusty but kind-hearted.

• Crustacean (noun): A class of arthropods (e.g., crabs, lobsters) that typically have a hard shell or crust.

• Encrust (verb): To cover or overlay with a crust, or to form a crust on.

  • The ancient vase was encrusted with jewels.

Synonyms

• Noun (Layer): Shell, rind, coating, covering, scab.
• Noun (Impertinence): Gall, nerve, audacity, cheek, impudence.
• Verb: Harden, solidify, cake, encrust.

Related Phrasal Verbs/Phrases

• Crust over: To become covered with a hard layer.
  • The wound began to crust over as it healed.

Related Idioms

• "The crust of the matter": A less common variant of "the crux of the matter," meaning the most essential part of an issue.
• "Have a crust": (Australian/NZ slang, often negative) To be cheeky or presumptuous.
  • You've got a crust asking for that!

Noun

1. the trait of being rude and impertinent; inclined to take liberties
2. a hard outer layer that covers something
3. the outer layer of the Earth

Verb

1. form a crust or form into a crust
   • The bread crusted in the oven