This is the 455th most frequent Polish word.
wcześniej
"Earlier" or "previously."
Here, 'wcześniej' is used to denote a prior moment earlier on the same day.
Spotkałem go wcześniej tego dnia.
I met him earlier that day.
The term 'wcześniej' in this context is implying that the knowledge existed prior to the moment of being informed.
Wiedziałem o tym wcześniej, zanim mi powiedział.
I knew about it earlier, before he told me.
The word 'wcześniej' indicates an action that occurred earlier than another point in time, demonstrating adverbial use for earlier time reference.