See decrepitude in Webster's New World Roget's A-Z Thesaurus II
noun
The condition of being infirm or physically weak:
debility, delicacy, delicateness, feebleness, flimsiness, fragileness, fragility, frailness, frailty, infirmity, insubstantiality, puniness, unsoundness, unsubstantiality, weakliness, weakness. See strong
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