義務 is read as ぎむ (gimu) and means duty.
ぎむ
gimu
ぎむきょういく
compulsory education
ぎむづけ
obligation
ぎむづける
to obligate
ぎむてき
compulsory
ぎむか
making obligatory
ぎむてきけいひ
mandatory expense
ぎむかん
sense of duty (obligation)
ぎむをかす
to place an obligation
さんだいぎむ
The Three Major Duties (education, work and payment of taxes)
ほうてきぎむ
legal obligation
つうちぎむ
obligation to give notice
ちゅういぎむ
duty of care