testosterone

noun

1. (countable, uncountable)A steroid hormone that stimulates development of male secondary sexual characteristics, produced mainly in the testes, but also in the ovaries and adrenal cortex.

   “Mammalian testes contain almost no testosterone because it is sent out into the body as quickly as it is made.”

   “The text recounts a 2011 experiment: Researchers tested 136 healthy young men’s testosterone levels, asked them about their political party affiliations, then gave them either a placebo or ten grams of AndroGel one percent, a high-end dose of a common form of testosterone often used in hormone replacement therapies.”

2. (countable, figuratively, uncountable)Manly behavior, often of an aggressive or foolishly reckless nature.

   “Mother encouraged James to rely more on intelligence and less on testosterone to deal with the neighbor's son.”

   “The MPS is a male orientated and misogynistic environment filled with testosterone, notches on bed posts and conquests.”