immemorially

/ˌɪməˈmɔriəli/
adverb
  1. From a time beyond memory or recorded history; for a very long time.
    • These customs have immemorially been passed down through generations.
    • The river has immemorially marked the boundary between the two regions.
    • The forest has immemorially been considered sacred by the local people.
Antonyms
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