The American Heritage® Dictionary of the English Language, 4th Edition
n. A white crystalline steroid hormone, C19H28O2, produced primarily in the testes and responsible for the development and maintenance of male secondary sex characteristics. It is also produced synthetically for use in medical treatment.
n. Steroid hormone produced primarily in the testes of the male; it is responsible for the development of secondary sex characteristics in the male.
n. Manly behavior, often of an aggressive or foolishly reckless nature.
the GNU version of the Collaborative International Dictionary of English
n. a steroid hormone (C19H28O2) produced mostly in the testes, which is responsible for producing the secondary sexual characteristics of males.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a potent androgenic hormone produced chiefly by the testes; responsible for the development of male secondary sex characteristics
Word Usage
"Joe Lockhart, former White House spokesman for Bill Clinton and now a Kerry adviser, says, If you want the easiest way to define the Bush doctrine, it's what I call the testosterone presidency."