Real Dictionary

calf
countable noun: A calf is a young cow.
countable noun: Some other young animals, including elephants and whales, are called calves.
countable noun: Your calf is the thick part at the back of your leg, between your ankle and your knee.

calf in American English 1
a young cow or bull
noun: the young of the domestic cow or other bovine animal

calf in American English 2
the fleshy back part of the leg below the knee
noun: the fleshy part of the back of the human leg below the knee

calf in British English 1
noun: the young of cattle, esp domestic cattle

calf in British English 2
noun: the thick fleshy part of the back of the leg between the ankle and the knee