the.com/full house

means A poker hand made of three cards of one rank plus two of another — a packed little household of cards, both occupied at once.

from The poker term rode in on an old figurative use of 'house' for a theater or gathering filled to capacity — a 'full house' meaning every seat taken. Card players borrowed that image sometime in the 1800s as poker's hand rankings took shape in the American frontier gambling scene, likening a hand stuffed with a triple and a pair to a venue with no empty seats left. The exact first use isn't pinned down, but the metaphor's lineage — from packed theaters to packed hands — is well established.