Adverb
insouciantly (comparative more insouciantly, superlative most insouciantly)
In an insouciant manner.
Yes, his unhealthy interest in nuclear weapons is terrifying, but at least he is not firing them off while insouciantly declaring that "some people say they'll cause Armageddon, but other people say they'll actually help crops grow, so I guess we'll see". Source: Internet
Which leader who entered World War I so insouciantly in 1914 would not have recoiled had he been able to imagine the world at its end in 1918? Source: Internet