In a way that seems to have no bottom or end; infinitely or endlessly.
From 'bottomless' (adjective, meaning having no bottom or limit) plus the adverb-forming suffix '-ly', first appearing in English around the 1600s.
The word 'bottomless' fascinated medieval thinkers who imagined bottomless pits as gateways to Hell—it represented the ultimate unknown, something that violated the natural order of the material world.
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