Lasting forever without ending or dying; eternal or permanent in nature.
From 'un-' (not) plus 'dying' (ceasing to live). The concept of immortality or permanence has been expressed through such negations for centuries in English poetry and literature.
Undying love, undying loyalty—we use this word for feelings we think will never go away, but it originally meant literally not able to die! Poets invented this term to describe eternal devotion.
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