Period
Term, Interval, Span
A period of time interval is still a period or interval of time.
きかん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
テスト期間中はあまりねれません。
I can't sleep much during exams.
わたしは人生のある期間を山おくですごした。
I spent a period of my life in a deep mountain.
コウイチの髭を期間限定で販売しています。
We're selling Koichi's mustache for a limited time only.