In a playful, silly, or whimsical manner; in the way of an antic.
From antic (a playful action) + -ally (suffix forming adverbs). This adverb form preserves the sense of the original Italian antico meaning fantastical.
Watching children play antically—with totally nonsensical movements and silly jokes—is actually how humans have always learned, and neuroscience shows that this kind of playfulness is essential for brain development.
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