trapeze: [19] Trapeze and quadruped are ultimately the same word: both mean etymologically ‘four feet’. Trapeze comes via French trapèze and late Latin trapezium (source of English trapezium [16]) from Greek trapézion ‘small table’. This was a diminutive form of trápeza ‘table’, literally ‘four-footed’ thing, a compound noun formed from tetra- ‘four’ and peza ‘foot’ (a relative of English foot).
The Greek mathematician Euclid used trapézion for a ‘table’-shaped geometrical figure, a quadrilateral. The application to the piece of gymnastic equipment, which evolved in French, alludes to the quadrilateral shape formed by the trapeze’s ropes and crossbar and the roof or other support it hangs from. => foot, quadruped
