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great-aunt vs. grandaunt

[greyt-ant, -ahnt] / ˈgreɪtˌænt, -ˌɑnt /

noun

great-aunts plural
  1. a grandaunt.

[grand-ant, -ahnt] / ˈgrændˌænt, -ˌɑnt /

noun

grandaunts plural
  1. an aunt of one's father or mother; great-aunt.