The state of no longer using something; when a tool, word, custom, or practice is stopped and forgotten.
From dis- (prefix meaning 'opposite of') + use (from Latin usus, meaning 'to use'). This word emerged in the 15th century as a straightforward way to describe abandonment of practices.
Words literally go into 'disuse' all the time—'thou' and 'thee' are in disuse in modern English, and 'ye olde' spelling is completely in disuse, which is why seeing it feels so ancient and strange to us.
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