from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Abnormal enlargement of the breasts in a male.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Excessive development of breasts in males, resembling the breast development in women.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. excessive development of the breasts in males; usually the result of hormonal imbalance or treatment with certain drugs (including some antihypertensives)
From gynaeco-, from Ancient Greek γῠναικός (gunaikos), a genitive of γυνή (gune, "woman") + μαστός (mastos, "breast"). (Wiktionary)