Burden
Responsibility
noun, する verb
You lose. Because of that, you have to carry this burden and responsibility.
ふたん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
10キロのお米を持ち上げることは、彼の腰の負担となった。
Lifting 10kg of rice was a burden on his lower back.