Fair and Square
Meaning
Honest and straightforward, especially of business dealings.
Origin
In the 16th century ‘square’ meant ‘fair and honest’ so ‘fair and square’ is tautological.
George Puttenham used that meaning of square in The arte of English poesie, 1589:
“[Aristotle] termeth a constant minded man – a square man.”
Francis Bacon’s essay Of Prophecies, 1604 is the first known use of ‘fair and square’:
“Faire, and square. The gamester calls fooles holy- day.”