tumor

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function; a neoplasm.
• noun A swollen part; a swelling.

from The Century Dictionary.

• noun A swell or rise of any kind.
• noun In medicine: A swelling; one of the four necessary accompaniments, according to the older pathologists, of inflammation—namely, color, dolor, rubor, et tumor (heat, pain, redness, and swelling).
• noun An abnormal prominence existing upon any of the cutaneous, mucous, or serous surfaces in any part of the body, and not due to acute inflammation.
• noun A swelling port or style; tumidity; bombast.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Med.) A morbid swelling, prominence, or growth, on any part of the body; especially, a growth produced by deposition of new tissue; a neoplasm.
• noun rare Affected pomp; bombast; swelling words or expressions; false magnificence or sublimity.
• noun a tumor which is inclosed in a membrane called a cyst, connected with the surrounding parts by the neighboring cellular substance.
• noun See under Fatty.
• noun one which does not of itself threaten life, and does not usually tend to recur after extirpation; a tumor which has not metastesized.
• noun a tumor which tends continually to spread, to become generalized in different parts of the body, and to recur after extirpation, and which, if left to itself, causes death.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun oncology, pathology An abnormal growth; differential diagnosis includes abscess, metaplasia, and neoplasia.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an abnormal new mass of tissue that serves no purpose