✨ Use insouciant when someone’s cool detachment makes them seem untouchably calm—or irresponsibly relaxed.
🔹 He strolled into the exam hall with an insouciant smile, unfazed by the ticking clock.
🔹 Her insouciant attitude toward deadlines often annoyed her more diligent colleagues.
From French insouciant — in- (“not”) + souciant (“worrying”), from souci (“care, worry”).