From Longman Dictionary of Contemporary Englishtie the knottie the knotinformalMARRY to get married → tie
Examples from the Corpus
tie the knot• The King lookalike couldn't help falling in love with Lynn Willoughby and yesterday they tied the knot.• Banks across the country tied the knot as a way to cut costs and boost earnings.• They tied the knot in a romantic ceremony on the banks of a fjord.• Lots of big companies tied the knot, while some huge ones split up.• Pressman will tie the knot with on, quickly followed by sales manager, , who marries on. 