An archaic or dialectal form meaning to make dull or to become blunt, no longer commonly used in modern English.
From Middle English blunnen, possibly related to Old Norse blunda meaning to shut one's eyes or drowse. The connection to 'blunt' suggests it may derive from the same root, with the meaning evolving from a state of dullness to the action of becoming dull.
This word is basically a ghost of English—it appears in medieval texts but vanished from everyday speech, replaced by the simpler 'blunt.' Linguists call these 'lost words,' and they teach us how language constantly prunes away older forms.
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