Noun
English Wikipedia has an article on:semitendinosus muscleWikipedia
semitendinosus (plural semitendinosi)
(anatomy) A fusiform muscle (one of the hamstrings) in the back of the thigh.
The biceps femoris has two heads: The long head has its origin on the ischial tuberosity together with the semitendinosus and acts on two joints. Source: Internet
The semitendinosus acts on two joints; extension of the hip, flexion of the knee, and medial rotation of the leg. Source: Internet