[knot] See: [TIE IN KNOTS], [TIE THE KNOT].

[knotty problem] {n. phr.} A very complicated and difficult problem to […]

[know] See: [FOR ALL ONE KNOWS], [GOD KNOWS] or [GOODNESS KNOWS] […]

[know a thing or two about] {v. phr.} To be experienced […]

[know enough to come in out of the rain] {v. phr.} […]

[know if one is coming or going] or [know whether one […]

[know in one's bones] See: [FEEL IN ONE'S BONES].

[know one in high places] {v. phr.} To be connected with […]

[know one is alive] {v. phr.} Not to notice a person. […]

[know one's onions] {v.} To be well acquainted with a subject.