knee jerk knee holm • knee joint · · · Info · Definitions · Synonyms · Characters · · knee jerk · · Text Common · · Latin · · Scripts 9 · · Length Definitions · · · (noun) a reflex extension of the leg resulting from a sharp tap on the patellar tendon. Synonyms: knee-jerk reflex, patellar reflex. · · Noun Definition 1 Synonyms · · · knee · · Synonym 1 knee joint · · Synonym 2 human knee · · Synonym 3 articulatio genus · · Synonym 4 genu · · Synonym 5 stifle · · Synonym 6 Characters · · space U+0020 e latin small letter e U+0065 j latin small letter j U+006A k latin small letter k U+006B n latin small letter n U+006E r latin small letter r U+0072