This is the 818th most frequent Slovak word.
radšej
"Radšej" means "rather" or "preferably" in English.
Here, 'radšej' indicates a preference or choice being made.
Radšej by som zostal doma, pretože vonku prší.
I would rather stay home because it's raining outside.
Here, 'radšej' is used to exhort a preference for one course of action over another.
Mal by si radšej zavolať než písať e-mail.
You should rather call than write an email.
In this case, 'radšej' again expresses a preference, specifically a decision considering the available alternatives.