Knot

a tight cluster of people or things

any of various fastenings formed by looping and tying a rope (or cord) upon itself or to another rope or to another object

a hard cross-grained round piece of wood in a board where a branch emerged

(of ships and wind) a unit of speed equal to one nautical mile per hour or about 1.15 statute miles per hour

something twisted and tight and swollen

soft lump or unevenness in a yarn

a sandpiper that breeds in the Arctic and winters in the southern hemisphere

make into knots

tie or fasten into a knot

tangle or complicate