亘古不变 gèngǔbùbiàn unchanging since ancient times Origin Definitions Defs Strokes Stroke Words Sentences Sents 亘古 亙古 gèngǔ throughout time from ancient times to the present; throughout history; eternal不变 不變 bùbiàn adjectiveverb unchanging constant; unvarying; fixed; in mathematics, this refers to an invariant