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sluggish; languid; listless; heavy (heart, legs, etc.); dull
bothersome; tiresome; pain-in-the-ass
今日は体が怠くて何もする気になれません。
My body is sluggish today and I can't move.
仕事がだるいなあと思う日もある。
There are days I think work is a drag.
風邪を引いたようで全身が怠い感じがする。
Don't push yourself when sluggish.