Do not confuse this word with canker or chancre. General term frequently used to indicate any of various types of malignant neoplasms, most of which invade surrounding tissues, may metastasize to several sites, and are likely to recur after attempted removal and to kill the patient unless adequately treated; especially, any such carcinoma or sarcoma, but, in ordinary usage, especially the former. [L. a crab, a cancer]