testosterone
n. uncountablen. a chemical in the body that helps develop male physical features like muscles and a deep voice. Both men and women have it, but men have much more.
n. a steroid hormone that stimulates development of male secondary sexual characteristics, produced mainly in the testes, but also in the ovaries and adrenal cortex.
The athlete's testosterone levels are checked regularly.
Doctors may prescribe hormone therapy if a patient's natural production of testosterone falls below a healthy range.
While primarily associated with physical strength and aggression, testosterone also plays a critical role in bone density and the regulation of mood across all genders.
From test(is) + -o- + -sterone (“steroid hormone”).
Uncountable in general reference; can be countable when referring to specific types or synthetic variations in a medical context.