Definition

1. Noun:
   • A pointed end or apex, especially where two curves meet: The word "cusp" most commonly refers to a point or a small, projecting part where two lines, curves, or surfaces meet.
   • A point of transition between two different states: In a figurative sense, "cusp" describes a critical point of change, such as the beginning of a new period or development.
   • A small elevation on the chewing surface of a tooth: In dentistry, "cusp" refers to one of the pointed parts on the crown of a tooth.
   • A triangular fold or flap in a heart valve: In anatomy, "cusp" denotes one of the segments of a heart valve that ensure one-way blood flow.

Examples of Usage

• Noun (Physical Point):
  • The cusp of the crescent moon was clearly visible.
  • The Gothic arch is defined by the meeting of two arcs at a sharp cusp.
• Noun (Point of Transition):
  • She was on the cusp of a major breakthrough in her research.
  • The company is on the cusp of a new era of innovation.
• Noun (Dentistry):
  • The dentist noted wear on the molar's cusps.
• Noun (Anatomy):
  • A malfunctioning aortic valve cusp can lead to heart problems.

Advanced Usage

• "On the cusp of": This is a common prepositional phrase meaning at the point of beginning or experiencing something significant.
  • He stood on the cusp of adulthood, full of both hope and anxiety.
  • The technology is on the cusp of revolutionizing the industry.

Variants and Related Words

• Cuspid (n): Another term for a canine tooth, which typically has a single pointed cusp.
• Cuspidate (adj): Having a sharp, pointed end.
• Bicuspid (n/adj): A tooth with two cusps; having two points.
• Tricuspid (n/adj): Referring to a valve in the heart with three cusps; having three points.

Synonyms

• Apex: The top or highest point.
• Verge: The edge or border, especially of a period or condition (e.g., ).
• Brink: The extreme edge, often before something dangerous or exciting (e.g., ).
• Tip: The pointed or rounded end of something.

Antonyms

• Base: The bottom support of something.
• Center: The middle point.
• Interior: The inner part.

Related Phrases

• Cusp of a curve (Mathematics): A point where a curve crosses itself or where it has a point of unusual tangency.
• Cusp catastrophe (Mathematics): A specific model in catastrophe theory describing sudden shifts in behavior.

Noun

1. small elevation on the grinding surface of a tooth
2. a thin triangular flap of a heart valve
3. point formed by two intersecting arcs (as from the intrados of a Gothic arch)