Not capable of being broken or fragmented; having the property of not breaking or fracturing easily.
From Greek 'a-' (not) + 'klastos' (broken, fragmented), literally meaning 'not broken,' used in scientific contexts to describe materials or substances resistant to fracturing.
Scientists use this term to describe certain materials, but it's so rare that it's almost disappeared from modern usage — a good reminder that language creates words exactly when they're needed, then forgets them when they're not.
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