Assigning numbers to things in sequence, or becoming numb or insensitive to something.
From Old English 'numb,' ultimately from Proto-Germanic 'numaz,' which described the sensation of paralysis or loss of feeling. The '-ing' suffix creates the present participle form.
The word 'number' actually has two completely different origins that merged in English—the counting 'number' comes from Latin 'numerus,' but 'numbering' as in 'becoming numb' comes from a totally different Germanic root about losing sensation.
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