Definition of agonist in English:

agonist

noun

  • 1Biochemistry
    A substance that initiates a physiological response when combined with a receptor.

    Compare with antagonist
    • ‘They may mimic naturally occurring steroids, act as hormone receptor agonists or antagonists or alter the enzymes responsible for hormone synthesis and degradation.’
    • ‘Medications that can reduce androgen levels include estrogen, gonadotropin-releasing hormone agonists, and glucocorticoids.’
    • ‘Opioid receptor agonists act at sites that are distributed throughout this circuit to produce analgesia.’
    • ‘For example, the highly potent opioid receptor agonist etorphine is not a medically useful drug because it can only be used a few times before the body becomes desensitized to the drug.’
    • ‘These observations provide support for the model that glucose and structurally related sugars are agonists of the Gpr1 receptor.’
  • 2Anatomy
    A muscle whose contraction moves a part of the body directly.

    Often contrasted with antagonist
    • ‘It's a matter of muscle aesthetics: The upper arm looks best when both its opposing muscle groups, the agonists and antagonists - that's bis and tris to you - carry a complementary amount of muscle.’
    • ‘Alternate between agonist and antagonist muscle groups (e.g… quadriceps and hamstrings), and alternate sides.’
    • ‘In addition, we believe that the agonist / antagonist muscle ratios are important values when considering how the scapula provides stability, mobility, and symptom-free function.’
    • ‘Muscles may act as agonists, antagonists, synergics and fixators.’
    • ‘The agonist and antagonist muscles work in concert to create muscular balance in the human body.’
  • 3

    another term for protagonist
    • ‘But now, replying to Harapha’s taunts with a startling invitation to combat, Samson is confident as the agonist was never before depicted.’
    • ‘To every agonist, there is an antagonist.’

Origin

Early 20th century: from Greek agōnistēs contestant (a sense reflected in English in the early 17th century), from agōn contest.

Pronunciation:

agonist

/ˈaɡənəst/