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slack; slackening; sagginess; flabbiness (skin, etc.)
dullness; letdown; depression; ennui
ロープにたるみがあると危険なので締め直した。
There was slack in the rope, which was dangerous, so I retightened it.
年齢とともに皮膚のたるみが気になり始めた。
As I aged, I began to notice the sagging of my skin.
チーム全体にたるみが出ていたため監督が喝を入れた。
The entire team had grown lax, so the coach gave them a stern talk.