Here are some synonyms for "lackadaisical":
* Careless
* Listless
* Indifferent
* Apathetic
* Halfhearted
* Uninterested
* Sluggish
* Unenergetic
* Lethargic
Here are some examples of how to use "lackadaisical" in a sentence:
* "The students were lackadaisical about their homework assignments."
* "His lackadaisical attitude towards his job led to his dismissal."
* "She gave a lackadaisical performance, failing to impress the judges."
Think of it as the opposite of someone who is enthusiastic, motivated, and engaged.