[ ˌgastrə(ʊ)'kni:mɪəs ]
(also ~ muscle )
■ noun ( plural gastrocnemii -mɪʌɪ ) Anatomy the chief muscle of the calf of the leg, which flexes the knee and foot.
Origin
C17: mod. L., from Gk gastroknēmia 'calf of the leg', from gaster, gastr- 'stomach' + knēmē 'leg' (from the bulging shape of the calf).