Meaning of unknownst in English:

unknownst

Pronunciation /(ˌ)ʌnˈnəʊnst/

adjective

Irish
  • Chiefly in adverbial clauses. Without being known; without the knowledge of; unknown to.

Origin

Early 19th century. Apparently from unknown + -s, in some forms with alteration after e.g. against, amongst, etc.