chief, head, leader

Tenchō era (January 824–January 834)

time for doing something / period of time / season

importance, consequence, significance

important, significant

extraordinary, unusual

very; extremely / exceedingly; tremendously

emergency

age, era, period (of time) / the times, spirit of the age / antiquity / a time in one's life, one's days (in college etc.)

history / the study of history