In a manner showing decline in strength, energy, or effectiveness; with visible waning or drooping.
From 'flagging' (present participle of flag, from Old Norse) plus the adverbial suffix '-ly', creating an adverb describing the manner of declining or drooping.
This is a rare adverb that captures motion in slow decline—imagine describing someone walking flaggingly toward the finish line, their enthusiasm visibly fading with each step.
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