the senate, the house of representatives, any formal meetings where a presenter stands before attendees, maybe. It's usually said when you're done making your point or your time is up to mean the 'floor' is available for the next speaker/presenter. It's always used when you hear words like bill, motion, etc.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
as far as I know, the expression explains that he or she is telling you that if you are in a presentation or something, its like the stage is yours so u can say what u want.