Age-defying is one of the highest-overlap phrases on the site because it sits at the border between consumer language and research language. Readers use it when they want a fast definition, brands use it when they want a broad promise, and researchers usually avoid it because it does not identify a specific mechanism or endpoint.
That makes it a useful directory topic. It can point people toward the shorter glossary definition, the fuller article on meaning and usage, and the companion claim-analysis page that explains how to read age-defying product promises without confusing them with biological age or healthspan research.
This entry is meant to be the stable landing point for that definitional search intent while deeper article and FAQ-style content expands around it.