
A nervous disorder in horses, causing a jerking movement, higher than the natural gait, of one or both hind legs, as if stepping over an invisible object.[181][page needed][194]
Found on
http://en.wikipedia.org/wiki/Glossary_of_equestrian_terms

Stringhalt is a sudden flexion of one or both hind legs in the horse, most easily seen while the horse is walking or trotting. It is most evident when the horse is backing up slowly, turning on the affected leg, or suddenly frightened. It can involve one or both hind legs of the horse. It is a spasmodic contraction of the lateral extensor tendons ...
Found on
http://en.wikipedia.org/wiki/Stringhalt

• (n.) An habitual sudden twitching of the hinder leg of a horse, or an involuntary or convulsive contraction of the muscles that raise the hock.
Found on
http://thinkexist.com/dictionary/meaning/stringhalt/
String'halt` noun (Far.) An habitual sudden twitching of the hinder leg of a horse, or an involuntary or convulsive contraction of the muscles that raise the hock. [ Written also
springhalt .]
Found on
http://www.encyclo.co.uk/webster/S/211

Condition in which the horse involuntarily hyperflexes the hock as it walks; the cause is unknown.
Found on
http://www.thehorse.com/Glossary.xhtml?L=S

a nerve disorder in horses, causing exaggerated flexing movements of the hind legs in walking.
Found on
https://www.infoplease.com/dictionary/stringhalt
No exact match found.