1. Beyond the reach of memory or recorded history.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• mememorial,
• mremorial,
• immorial,
• inmemorial,
• ummemorial,
• jmmemorial,
• kmmemorial,
• ommemorial,
• 9mmemorial,
• 8mmemorial,
• ikmemorial,
• imemorial,
• immmorial,
• immeorial,
• imemmorial,
• immemmorial,
• immeoorial,
• immemorialy,
• insesorial,
• Imemorialy

• memorial,
• immoral.

The adjective form of the word "immemorial" is "immemorial".

The plural form of the word "immemorial" is "immemorials".

The singular form of "immemorial" is "immemorial". This word does not have a distinct singular form since it is an adjective that typically does not change in form to indicate singularity or plurality.