IPA: /ˌɪnˈsuːsiəntli/
KK: /ɪnˈsuːsiəntli/
In a relaxed and carefree way, showing a lack of concern or worry.
She insouciantly strolled through the park, enjoying the sunny day without a care in the world.
Insouciantly → It is formed from "insouciant" (from French *insouciant*, meaning carefree or unconcerned) and the suffix "-ly" (meaning in a manner of). The word "insouciantly" means in a carefree or unconcerned manner.
Think of being 'carefree' ('insouciant') and how the '-ly' makes it describe the way someone acts. This helps you remember that 'insouciantly' means acting in a carefree manner.
No commonly confused words.