形容詞 listless:

1. lacking zest or vivacity
2. marked by low spirits; showing no enthusiasm
   同義詞：dispirited

1. I feel dizzy [groggy, listless, sore all over, a bit chilly].
   我頭暈[身子軟，沒有精神，全身酸疼，有一點涼]。
2. Reacted to the latest crisis with listless resignation.
   對最近的危機所作的反應(yīng)是無精打采的放棄
3. Because of the death of his mother he is listless all day.
   因為母親的去世，他整天無精打采的。
4. She was very listless after her illness.
   她病后懶洋洋的。

list.less

adj.（形容詞）
Lacking energy or disinclined to exert effort; lethargic:
無精打采的：缺乏精力或不愿努力；遲鈍：
例句：
reacted to the latest crisis with listless resignation.
對最近的危機所作的反應(yīng)是無精打采的放棄

來源：
Middle English listles
中古英語 listles
probably from liste [desire] from listen [to desire] * see list 5
可能源自 liste [欲望] 源自 listen [渴望] *參見 list5
-les, -lesse [-less]
-les, -lesse [后綴，表.無，不.]

【引伸】
list.lessly
adv.（副詞）
list.lessness
n.（名詞）