Wikipedia
The Senior Wrangler is the top mathematics undergraduate at Cambridge University in England, a position which has been described as "the greatest intellectual achievement attainable in Britain."
Specifically, it is the person who achieves the highest overall mark among the Wranglers – the students at Cambridge who gain first-class degrees in mathematics. The Cambridge undergraduate mathematics course, or Mathematical Tripos, is famously difficult.
Many Senior Wranglers have become world-leading figures in mathematics, physics, and other fields. They include George Airy, John Herschel, Arthur Cayley, James Inman, George Stokes, Isaac Todhunter, Morris Pell, Lord Rayleigh, Arthur Eddington, J. E. Littlewood, Frank Ramsey, Donald Coxeter, Jacob Bronowski, Lee Hsien Loong, Kevin Buzzard, Christopher Budd and Ben Green.
Senior Wranglers were once fêted with torchlit processions and took pride of place in the University's graduation ceremony. Years in Cambridge were often remembered by who had been Senior Wrangler that year.
The annual ceremony in which the Senior Wrangler becomes known was first held in the 18th century. Standing on the balcony of the University's Senate House, the examiner reads out the class results for mathematics, and printed copies of the results are then thrown to the audience below. He no longer announces the students' exact rankings, but he still identifies the Senior Wrangler, nowadays by tipping his academic hat when he reads out the person's name.
Usage examples of "senior wrangler".
Although my father and mother considered the highlight of the year to be my passing out as senior Wrangler with the offer of a Prize fellowship at Trinity, I thought Dad's investiture at Buckingham Palace wasn't to be sneezed at.
And I just bet you had one of those swanky fancy nutcrackers like a big thumbscrew,' said the Senior Wrangler.
During all this excursion, she condescended to say civil things to him: she quoted Italian and French poetry to the poor bewildered lad, and persisted that he was a fine scholar, and was perfectly sure he would gain a gold medal, and be a Senior Wrangler.