From Hyde Flippo,
Your Guide to German Language.
German Idioms and Expressions
English also has many "knot" expressions, but the German versions often mean something different from the English. There are also the usual differences between American and British usage. The British expression "tie a knot in your handkerchef" is the same as the German einen Knoten ins Taschentuch machen, but Americans "tie a string around their fingers" to remind them of something. While a "Gordian knot" is the same in German (ein Gordischer Knoten), because it is named for an ancient Greek king, "tying the knot" in German is usually expressed simply as heiraten (to get married).
Even without being used in an idiom, the English word "knot" has more meanings than you probably ever realized:
knot = string or rope tied together
knot = a bond or union; marriage (der Bund; see "tie the knot" below)
knot = lump, knob (der Knoten, die Verdickung)
knot = hair bun (der Haarknoten)
knot = an interlacement of flexible parts
knot = a cluster of persons or things (der Knäuel)
knot = junction, node (der Knotenpunkt)
knot = a tight constriction
knot = something hard to solve (ein Gordischer Knoten)
knot = one nautical mile per hour (der Knoten)
knot = a darker, dense section in a piece of lumber (der Ast)
knot = sandpiper-like bird (Tringa canutus) in the snipe family, also called robin snipe, gray snipe, or red-breasted ash-colored sandpiper
This great variety of meanings is the reason there are many ways to express "knot" in German.
Below you'll find a glossary of German and English "knot" words, plus expressions that use "knot" or "Knoten" - with example sentences and explanations where needed.
English "knot" Expressions and Idioms in German