In "x01" dart games (such as 301), a score of a single 20, a single 5 and a single 1, for a total of 26 points.
The phrase originated in the distant past, when the standard rate for a bed-and-breakfast in England was 2 shillings and 6 pence ("two and six").
Tyrannosaurus Allen: "Hmm yes, I do feel hydrated! C'MON WORLD I'm Tyrannosaurus Allen AND I'll HAVE YOU FOR BREAKFAST!"
"murray is my breakfast"
"i'd love to lick that breakfast stamp"