unbeknownst

/ˌʌnbɪˈnoʊnst/
adjective
  1. Without someone's knowledge; unknown to someone. (Same meaning as 'unbeknown', but less common.)
    • Unbeknownst to the team, their manager had already resigned.
    • Unbeknownst to him, his friends were planning a surprise party.
    • She continued her journey, unbeknownst to the dangers ahead.
Antonyms
What does "unbeknownst" mean? | whatsthatwordmean | whatsthatwordmean