In a manner that blurs or causes something to become unclear; in a way that obscures or makes indistinct.
From the present participle 'blurring' (from the verb 'blur') plus the adverbial suffix '-ly.' This creates an adverb describing the manner of blurring action.
Stacking suffixes like '-ing' + '-ly' shows how English builds complexity from simple elements. You could theoretically add more: 'un-blurringly,' 'most-blurringly.' This modularity is why a language with only 26 letters can express infinite ideas.
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