Knot - n.1 a A compact intersection of interlaced material, such as cord, ribbon, or rope. b A fastening made by tying together lengths of material, such as rope, in a prescribed way. 2 A decorative bow of ribbon, fabric, or braid. 3 A unifying bond, especially a marriage bond. 4 A tight cluster of persons or things. 5 A feeling of tightness. 6 A complex problem. v.1 To tie in or fasten with a knot or knots. 2 To snarl or entangle.