The quality or state of being biting; sharpness or severity in tone, manner, or effect that cuts or wounds.
From 'biting' plus the noun-forming suffix '-ness', which converts adjectives into abstract nouns. The term evolved from the physical concept of biting to metaphorical descriptions of cutting remarks or cold weather.
The 'bitingness' of a winter wind is literally about how it stings exposed skin, but when poets describe the bitingness of a critic's words, they're borrowing that physical pain metaphor to describe emotional injury.
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