Something that is unknown to someone or something happening without someone's knowledge.
Examples:
She went to the party unbeknown to her parents.There was a surprise waiting, unbeknown to the guests.Unbeknown to us, the plan was already in action.
Synonyms:
Antonyms:
Unbeknownst
Not known or unnoticed by someone
Examples:
Unbeknownst to him, they planned a surprise party.She slipped away, unbeknownst to the bustling crowd.Unbeknownst to many, the artist lived in seclusion.
Synonyms:
Antonyms:
Ways to tell them apart:
Unbeknown and unbeknownst both mean without someone's knowledge, but they differ in formality and usage.
Unbeknown is the more common version used in modern English, and is typically used on its own.
Unbeknownst tends to be used in older literature or in a more playful or dramatic context.
Remember that both words involve some sort of hidden or secret action.
If in doubt, unbeknown tends to be the safer choice in professional or formal writing.