The Collaborative International Dictionary
Syndesmosis \Syn`des*mo"sis\, n.; pl. Syndesmoses. [NL., fr. Gr. ? a bond; ? together + ? a bond, fr. ? to bind.] (Anat.) An articulation formed by means of ligaments.
Wiktionary
n. (context anatomy English) A slightly movable articulation or joint where the contiguous bony surfaces are united by an interosseous ligament.
Wikipedia
A syndesmosis is a slightly movable fibrous joint in which bones such as the tibia and fibula are joined together by connective tissue. Examples include the distal tibiofibular joint as well as the radioulnar joint. Injuries to the ankle syndesmosis are commonly known as a "high ankle sprain". Although the syndesmosis is a joint, in the literature the term syndesmotic injury is used to describe injury of the syndesmotic ligaments. It comes from the Greek σύν, syn (meaning "with") and δεσμός, desmos (meaning "a band"). Syndesmosis sprains have received increasing recognition during recent years because of a heightened awareness of the mechanism, symptoms, and signs of injury.