noun
jealousy of others' romantic happiness; unwarranted jealousy
A yojijukugo describing jealousy toward people who are in love or happy together, even when it does not directly concern oneself. Rare and literary; not used in everyday conversation.
彼は友人の結婚に法界悋気を感じているようだ。
He seems to feel unwarranted jealousy about his friend's marriage.
嫉妬 is the common word for jealousy in general, while 法界悋気 is a rare, literary yojijukugo specifically for jealousy of others' romantic happiness that does not involve oneself.
A yojijukugo combining 法界 (the world, all things) and 悋気 (jealousy). The exact historical derivation is uncertain, but the phrase figuratively expresses jealousy toward the romantic happiness of others in the world.