The state of being very old, worn-out, and in poor condition; extreme age or weakness.
From Latin 'decrepitus' (very old) with the suffix '-ude' (from Latin '-tudo'), which creates nouns describing states or conditions. This formal term has been used since the 17th century.
While 'decrepitness' and 'decrepitude' mean almost the same thing, 'decrepitude' sounds more formal and poetic—philosophers use it to describe the decline of civilizations!
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