turnip

Concise Oxford English Dictionary © 2008 Oxford University Press:
turnip/ˈtɜːnɪp/

▶noun

• 1 a round root with white or cream flesh which is eaten as a vegetable and also has edible leaves.

• 2 the European plant of the cabbage family which produces the turnip. [Brassica rapa.]

– derivatives
turnipy adjective.

– origin C16: first element of unknown origin + neep.