Casually adverb – In an unconcerned manner. Lightly and casually are semantically related In some cases you can use "Lightly" instead an adverb "Casually". Nearby Words: casual, casualty
He talks casually with pirates powerful enough to singlehandedly take out an army, never showing the slightest concern even in a battlefield; in short, he takes everything incredibly lightly.
It would be impossible to choose between these two answers and it was an answer that shouldn't be taken lightly, unlike the contestant before them who casually gave his answer thinking it would please the elderly woman.