Definition

1. Noun:
   • A quadrilateral with no parallel sides: In geometry, a "trapezium" is a four-sided flat shape (quadrilateral) where no two sides are parallel. (Note: This is the primary definition in British English. In American English, this shape is typically called a "trapezoid," and a "trapezium" refers to a quadrilateral with one pair of parallel sides.)
   • The wrist bone on the thumb side of the hand: In anatomy, the "trapezium" is one of the eight small carpal bones in the wrist. It is located at the base of the thumb and connects to the first and second metacarpal bones.
   • A multiple star in the constellation of Orion: In astronomy, the "Trapezium" is a famous cluster of four bright stars located within the Orion Nebula.

Usage Examples

• Noun (Geometry):

  • The quadrilateral he drew was a trapezium because none of its sides were parallel.
  • In British textbooks, a trapezium is defined as having no parallel sides.

• Noun (Anatomy):

  • Arthritis in the trapezium can cause pain at the base of the thumb.
  • The surgeon carefully realigned the fractured trapezium.

• Noun (Astronomy):

  • The Trapezium stars are young, hot stars illuminating the Orion Nebula.
  • Through the telescope, we could clearly see the four stars of the Trapezium.

Advanced Usage

• "Trapezium bone": The full anatomical term for the wrist bone.

  • The stability of the thumb joint depends on the trapezium bone.

• "Trapezium cluster": Refers specifically to the star cluster in Orion.

  • The Trapezium cluster is a popular target for amateur astronomers.

Variants and Related Words

• Trapezia (n): An accepted plural form of "trapezium," especially in scientific contexts.

  • The x-ray showed irregularities in both trapezia.

• Trapezoid (n): In American English, a quadrilateral with one pair of parallel sides. In British English, this shape is called a "trapezium."

  • The area of a trapezoid is calculated using the lengths of its two parallel sides.

Synonyms

• Quadrilateral (n): A general term for any four-sided polygon. (Geometry)
• Carpal bone (n): A general term for any of the eight bones in the wrist. (Anatomy)
• Star cluster (n): A group of stars. (Astronomy)

Related Phrases

• "First carpometacarpal joint": The joint formed between the trapezium bone and the first metacarpal bone (the thumb bone).
  • Osteoarthritis commonly affects the first carpometacarpal joint.

Related Idioms

(There are no common idioms directly using the word "trapezium.")

Noun

1. the wrist bone on the thumb side of the hand that articulates with the 1st and 2nd metacarpals
2. a multiple star in the constellation of Orion
3. a quadrilateral with no parallel sides