# Main definitions of trapezium in US English:

: trapezium1Trapezium2

## trapezium1

### nounPlural trapeziums, Plural trapezia

• 1Geometry

• ‘What is the length of the top edge, x, in this new trapezium?’
1. 1.1North American A quadrilateral with no sides parallel.
Compare with trapezoid
• ‘With the help of square, rhombus, rectangle, parallelogram, trapezium, equilateral, isosceles, diamond and kite shapes the direct and indirect approaches to teach the Pythagoras Theorem and other mathematical concepts is possible.’
• ‘On plan the auditorium is a trapezium rising three levels high inside its rectangular confines with rehearsal and dressing rooms fitted around two edges.’
2. 1.2British A quadrilateral with one pair of sides parallel.
• ‘Also, the gold point makes the three equal-length sides SP = PQ = QR in the resulting trapezium so it is trisosceles (to use Scott's phrase) and so is a special isosceles triangle.’
• ‘They have been made in many shapes: triangular or trapeziform, ‘pig's head’ shape (a trapezium with concave ‘cheeks’, popularly known in Italy as strumento di porco), wing or harp-shaped, or rectangular.’
• ‘The types of shapes for which the area is calculated include triangles, rectangles, circles, trapeziums.’
• ‘In particular he finds, in book 1, the centre of gravity of a parallelogram, a triangle, and a trapezium.’
• 2Anatomy
A bone in the wrist below the base of the thumb.

• ‘These involved, in addition to the base of the first carpometacarpal joint, the trapezium, navicular, surrounding fascial structures or the abductor pollicis brevis muscle.’
• ‘Occasionally, a slip also passes to the fourth metacarpal or to the trapezium.’
• ‘The distal row of carpals includes the hamate, capitate, trapezium, and trapezoid, which are closely approximated to the metacarpals.’
• ‘The insertion may ascend on the lateral face of the radius or may be extended distally to the navicular, trapezium, or base of the third metacarpal bone.’
• ‘The movements of the thumb are dictated by the saddle-shaped articular surface of the base of the first metacarpal, which articulates with the trapezium.’

### Origin

Late 16th century: via late Latin from Greek trapezion, from trapeza ‘table’. The term has been used in anatomy since the mid 19th century.

## trapezium

/trəˈpēzēəm//trəˈpiziəm/

## Main definitions of trapezium in US English:

: trapezium1Trapezium2

## Trapezium2

### proper noun

the Trapezium
Astronomy
• The multiple star Theta Orionis, which lies within the Great Nebula of Orion and illuminates it. Four stars are visible in a small telescope and two more with a larger telescope.

## Trapezium

/trəˈpiziəm//trəˈpēzēəm/