piàn-siòng變相

covert

covert; in a disguised form; concealed; to change phase; to transform; new shapes and forms generated by transformations

physics

English Wiktionary, “變相” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E8%AE%8A%E7%9B%B8 · confidence: Medium (Wiktionary, Hokkien)