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unavoidably; inevitably; necessarily; reluctantly; against one's will
やむを得ず参加した。
I participated reluctantly.
やむを得ず引き受けたが、内心は不満だった。
I took it on reluctantly, but was inwardly dissatisfied.
予算が足りないため、やむを得ず計画を縮小することになった。
Due to insufficient funds, the plan had to be scaled back out of necessity.