knot
noun [ C ]
uk/nɒt/ us MEASURES
a measure of the speed of ships, aircraft, or movements of water and air. One knot is approximately 1.85 kilometres per hour:
The flight takes an hour, flying at 140 knots.
tie the knot
if two or more companies tie the knot, they join to become one company:
The two airline companies finally agreed to tie the knot after last-minute haggling over ownership.