Excessive development of the breasts in males

• Usually the result of hormonal imbalance or treatment with certain drugs (including some antihypertensives)

Wikipedia Word definitions in Wikipedia
Gynecomastia is a common disorder of the endocrine system in which there is a non-cancerous increase in the size of male breast tissue. Most adolescent boys, up to 70%, have some breast development during puberty . Newborn and adolescent males often experience ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1881, from Greek gyne (see queen ) + mazos "breast," variant of mastos (see masto- ) + abstract noun ending -ia .

Wiktionary Word definitions in Wiktionary
n. (context American spelling medicine English) Excessive development of breasts in males, resembling the breast development in women.

WordNet Word definitions in WordNet
n. excessive development of the breasts in males; usually the result of hormonal imbalance or treatment with certain drugs (including some antihypertensives)