震旦 zhèndàn Cinasthana Definitions Defs Origin Strokes Stroke Words Sentences Sents 震旦纪 zhèndànjì Sinian Period Sinian period, a geological period in the late Precambrian era roughly 800 to 542 million years ago.震旦鸦雀 zhèndànyāquè reed parrotbill a bird species native to East Asia, specifically the reed parrotbill (Paradoxornis heudei)