chord·al /ˈkɔrdḷ/
  chord·al /ˈkɔrdḷ/ 形容詞
  索的,脊索的
  Chor·dal a. Of or pertaining to a chord.
  ◄ ►
  chordal
       adj : relating to or consisting of or emphasizing chords; "chordal
             assonance in modern music"; "chordal rather than
             contrapuntal music"