Definition of trigon in US English:



  • 1

    archaic term for triangle
    • ‘It is therefore not enough to count trigons by signs or to expect a true square from signs at intervals at four’.’
    • ‘You can also have a cylinder cone roof wedge trigon prism.’
    • ‘This is not easy for me to contemplate and has troubled me for many years - I recall my reluctance to accept the theory that some trigons on a diamond octahedron were produced by dissolution.’
    1. 1.1 An ancient triangular lyre or harp.
      • ‘When you hear the sound of the horn, the pipe, the lyre, the trigon and drum and all the musical instruments, you are commanded to bow down and worship.’
      • ‘Hence, the early Christians were unwilling to bend the knee when they heard the sound of the horn, pipe, lyre, trigon, harp, drum, and entire musical ensemble.’
    2. 1.2 A triangular cutting region formed by three cusps on an upper molar tooth.
      • ‘The trigon + talon basin forms a broad, shallow depression, bordered posterolingually by the postprotocone fold + postcingulum and covered by crenulated enamel; no postprotocrista or hypocone is evident.’
      • ‘The basic triangular units with three cusps are the trigon and trigonid.’
      • ‘The enamel is extensively crenulated and the postprotocrista low and subdivided so that the trigon and talon basins are nearly confluent, as in P. canpacius.’
      • ‘The preprotocrista is weak and the postprotocrista absent; the trigon and talon basins are fully confluent.’
      • ‘As the trigon and trigonid meet, they slide past one another, shearing the food item on the edges of the molars as shown.’


Early 17th century (in the sense ‘triangle’): via Latin from Greek trigōnon, neuter of trigōnos ‘three-cornered’.