形相 けいそう Meanings Noun form; appearance form (in Aristotelianism); eidos See also: 質料 (しつりょう). Kanji 形 shape. Read as ケイ. 相 mutual. Read as ソウ. Words containing 形相 形相因 (けいそういん) formal cause (one of Aristotle's four fundamental types of answer to the question "why?") Jinuma: Japanese Dictionary · Word lists