(pathology) A benign or malignant tumour, especially of the gonads, that arises from germ cells and consists of different types of tissue such as skin, hair, or muscle.
1972, Patrick O'Brian, Post Captain:‘What is a teratoma?’ asked Jack, holding the object in his hand. ‘A kind of grenado?’ ‘It is an inward wen, a tumour: we find them, occasionally, in the abdominal cavity. Sometimes they contain long black hair, sometimes a set of teeth: this has both hair and teeth.’
