Lassitude (noun)

1. A state of physical or mental weariness; lack of energy or enthusiasm.
2. A state of listlessness or indolence.

Origin:

Late middle english: from old french, from latin lassitudo, from lassus "weary".

Examples:

1. The heat of the day caused a lassitude that made it difficult to focus on work.
2. The patient's illness left her in a state of lassitude and weakness.
3. The tropical climate induced a feeling of lassitude in the travelers.
4. The dancers moved with a lassitude grace.
5. The slow music and dim lighting created a sense of lassitude in the room.