A German word most often translated (if translated at all) as nodal point or, much more loosely, as switch word.
In the works of Sigmund Freud, a knotenpunkt was an overlap within an individual's psyche between two or more words, concepts, perceptions, themes, or ideas. In free association, and especially in dreams, one may jump from one path of thought to another by way of these knotenpunkts.
A knotenpunkt could have links to many different words and concepts; these connections might be caused by a number of different factors. You might go from "violation" to "flowers" because (according to Freud) they are naturally connected in the subconscious, but you might also go from "violet" to "violent" because of phonetic similarity. All of these links are knotenpunkts; not all of these links are useful. Nevertheless, studying these junctions can be very revealing as long as you are aware which connections are important and which are incidental. It is because of connections such as these that Freud thought it was valid to interpret a dream about flowers as really being about violation. A complete understanding of these connections might well require a thorough understanding of the patient's past experiences, as many connections are unique to the individual.
In other words, a node of the mind.