三分損益 [－－损－]

Jyutping saam1 fan1 syun2 jik1
Pinyin sān fēn sǔn yì

Definitions (Wiktionary)
  1. noun
    The “Method of Subtracting and Adding Thirds” in ancient Chinese music theory, which involves alternately rising a fifth and descending a fourth through the subtraction or addition of a third of the length of the preceding pitch pipe.