noun
the whole week; all week
Emphasizes the entire week without interruption; often used with verbs like 休む, かかる, 続く.
丸一週間、雨が降り続いた。
It rained for the whole week.
彼は丸一週間休みを取った。
He took the whole week off.
一週間 simply means 'one week', while 丸一週間 emphasizes the entire duration without exception.
Compound of 丸 (まる, 'whole, complete') + 一週間 (いっしゅうかん, 'one week').