Weak, feeble, or lacking strength or vigor; of poor quality or insignificant.
From Latin debilis (weak, feeble), which may derive from de- (away, down) plus habilis (able, fit), literally meaning 'not able.' The word entered English through French.
This lovely old word has almost vanished from English, replaced by 'feeble' or 'weak,' but it survives in 'debilitate' and medical terminology—it's an ancestor word that gave birth to more common descendants!
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