Meaning : Without someone's knowledge.
Example :
Unbeknownst to me, she made all the arrangements.
Synonyms : unbeknown
Meaning : (usually used with `to') occurring or existing without the knowledge of.
Example :
A crisis unbeknown to me.
She had been ill for months, unbeknownst to the family.
Synonyms : unbeknown
Unbeknownst ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Hindi. Unbeknownst ka matlab kya hota hai?