Here are some synonyms for insouciant:
* Carefree
* Relaxed
* Unconcerned
* Nonchalant
* Easygoing
* Blithe
* Lighthearted
Here are some examples of how you might use "insouciant" in a sentence:
* She had an insouciant air about her, as if nothing bothered her.
* He strolled through the park with an insouciant swagger.
* The band played with an insouciant rhythm, making the audience sway to the music.
It's important to note that "insouciant" can sometimes have a slightly negative connotation, implying a lack of seriousness or responsibility. However, it can also be used in a positive way to describe someone who is charming and carefree.