Gastrocnemius

gastrocnemius \ˌgas-(ˌ)träk-ˈnē-mē-əs, -trək-\ noun: the largest and most superficial muscle of the calf of the leg arising by two heads from the condyles of the femur and attaching to a tendon that becomes part of the Achilles tendon

Etymology: New Latin, from Greek gastroknēmē calf of the leg, from gastr- stomach + knēmē shank

This word is noteworthy because of its etymology: belly of the leg. How cool is that? A leg-belly.