Languid; listless — feeling physically or mentally heavy and lacking energy.
昨日の二日酔いで今朝はとてもけだるい。
I feel very languid this morning from yesterday's hangover.
夏の午後はいつもけだるくなってしまう。
Summer afternoons always make me feel listless.
彼はけだるい表情で席に着いた。
He took his seat with a languid expression.