In a manner that produces crunching sounds; with a series of crisp, snapping noises.
From crunching (present participle of crunch) + -ly (adverbial suffix). The -ly suffix, from Old English -lice, converts adjectives and participles into adverbs indicating manner.
This adverb creates a wonderful phonetic cascade—each sound reinforces the meaning, making it almost impossible to say without actually hearing a crunch in your mind!
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