time for doing something / period of time / season

important, significant

importance, consequence, significance

very; extremely / exceedingly; tremendously

extraordinary, unusual

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

the Mesolithic

Short for 中国地方 (Chūgoku chihō): the Chūgoku region of Japan