keep something secret, to hold something close so no one else can see it
Though it was just a friendly game of Go-Fish, Henry kept his cards close to the vest, not letting anyone else see which cards he held.
He played the murder close to the vest so he could work out all the details before the police found out.
Taking up a life of prostituion
Mentioned in James Joyce's Eveline
Because Frank left her, she's a fallen woman. She doesn't have anything left but to go to Buenos Aires.