Here are some synonyms for languid:
* Listless
* Lethargic
* Drowsy
* Indolent
* Relaxed (in a negative way)
* Faint
* Weak
Examples:
* The heat made him feel languid and unable to move.
* She had a languid smile that suggested she was bored.
* The music created a languid atmosphere.
* His voice was languid and full of boredom.
Note: "Languid" can also be used to describe something that is graceful or elegant in a slow, relaxed way. However, this usage is less common than the one described above.