In a sticky, viscous, or adhesive manner; with a glue-like quality.
From glutinous plus the adverb-forming suffix -ly. The -ly suffix transforms adjectives into adverbs describing how something is done or exists.
Adverbs made from rare adjectives like this one are usually found only in technical writing or fiction trying for a specific atmospheric effect—imagine describing something moving 'glutinously' through the darkness.
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