Gastrocnemius n. : The muscle which makes the greater part of the calf of the leg.

Example:
What is the difference between the Gastrocnemius and plantaris muscle in a frog?

Taxonomy
Gastrocnemius muscle, muscle, layer, compartment, free encyclopedia, tendon, achilles tendon, soleus muscle, tibia, knee, calf muscle, contractions, Ph.D, articular surfaces, tibial nerve, nerve roots, Anatomy, torn calf muscle.

Defination from the web:
gastrocnemius (pronounced /ˌɡæstrɒkˈniːmiəs/ or /ˌɡæstrəˈniːmiəs/) muscle is a very powerful superficial muscle that is in the ... superficial · triceps surae (gastrocnemius, soleus, Achilles tendon) · plantaris ...