unbeknown

American  

[uhn-bi-nohn] / ˌʌn bɪˈnoʊn /

Also unbeknownst

adjective

1. unknown; unperceived; without one's knowledge (usually followed byto ).

---

unbeknown British  

/ ˌʌnbɪˈnəʊn /

adverb

1. Also (esp Brit): unbeknownst. without the knowledge (of a person)

   unbeknown to him she had left the country

---

adjective

1. rare not known (to)

Etymology

Origin of unbeknown

1630–40; un- ¹ + beknown ( late Middle English beknowe, past participle of beknowen ); see be-, known

---

Example Sentences

See Examples For:

unbeknown

These were simple concepts to understand, but unbeknown to almost everybody for generations, they might have been flawed.

From The Wall Street Journal ● Apr. 16, 2026

He then added a a small line of code somewhere in the thousands of lines of letters, numbers and symbols into my project, unbeknown to me.

From BBC ● Feb. 12, 2026

A week earlier Sturdivant had also begun communicating on a social-media platform with someone who, unbeknown to him, was an undercover officer.

From The Wall Street Journal ● Jan. 2, 2026

So how did the Earwigs gain this unlikely cult following unbeknown to its founding member?

From Los Angeles Times ● Sep. 6, 2025

We were waiting for Mr. Mwakangale of the Tanganyika African National Union, a member of Parliament, and unbeknown to us he had already called looking for us.

From "Long Walk to Freedom" by Nelson Mandela

Random Word

Spin the wheel and learn a new word!

---