Meaning of the word hitherto in English

What does hitherto mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

hitherto

US /ˌhɪð.ɚˈtuː/
UK /ˌhɪð.əˈtuː/

Adverb

until now or until the point in time under discussion

Example:
The research has revealed facts hitherto unknown.
He had hitherto been a quiet and unassuming man.