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REFERENCE

testosterone

n.
US //ˌtɛsˈtɑstɝˌoʊn// UK //tɛstˈɒstəɹˌəʊn// testos·terone
  1. 1 the hormone (n.)
    B2 Upper Intermediate Technical Medicine

    a natural chemical in the body that helps develop muscles, a deep voice, and other male features.

    a steroid hormone that stimulates the development of male secondary sexual characteristics, produced primarily in the testes.

    Example

    The doctor checked his testosterone levels to see why he felt so tired.

    Example

    Synthetic testosterone is sometimes prescribed to patients with hormonal deficiencies, though its use must be strictly monitored by a specialist.

    Usage

    Uncountable in general contexts; countable when referring to specific types or measurements.
  2. 2 aggressive behavior (n.)
    C1 Advanced Informal

    behavior that is very aggressive, competitive, or risky, often associated with men.

    a figurative reference to qualities of aggression, competitiveness, or bravado traditionally associated with masculinity.

    Example

    The meeting was full of testosterone, with everyone shouting to prove they were right.

    Example

    The locker room was thick with testosterone as the players prepared for the championship final, their adrenaline-fueled shouting echoing off the walls.

    Teacher's tip

    This sense is often used with a slightly negative or critical tone to describe men acting in an overly competitive or foolish way.
Origin

From test(is) + -o- + -sterone (“steroid hormone”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Last updated June 20, 2026