A person having the qualities of always having good intentions, always generous and willing to help, great sympathy and overall well mannered demeanor.
"He's always the one buying his friends drinks, Justin's such a saint."
"She has the heart of a saint, always puts others needs before her own."
This refers to a boss (patron/matron), a person that is honored with all the glory in a successful act/gathering.
He/she is the leader of an Oshozondi movement(ballers).
When a man gets lucky at the gay bar on a Sunday night and gets so well rogered he doesn't go in to work on the Monday. His day off is known in the gay community as Saint Briggsy's Day.
I went home with two fat blacktrannieslast night and my arse is rawer than sushi. I'm gonna have a Saint Briggsy's Day.