Hormone was coined during a lecture. On June 20, 1905, Ernest Starling stood before the Royal College of Physicians in London and introduced the word to describe chemical substances produced in one part of the body that travel through the blood to stimulate activity in another. He derived it from Greek horman, meaning to set in motion or to urge on, capturing the idea of a chemical messenger that arouses a distant organ into action.
Starling did not arrive at the word alone. He consulted William Hardy, a Cambridge colleague with classical training, who suggested the Greek verb. The choice was precise — Greek horme means an impulse or rush, and the present participle hormon carries the sense of something that is actively stimulating. The word fit the biological concept perfectly: hormones are chemical agents of arousal and regulation.
The concept preceded the word. Starling and his colleague William Bayliss had discovered secretin in 1902, a substance released by the small intestine that stimulates the pancreas to produce digestive juices. This was the first hormone to be identified, though the word did not yet exist. Earlier researchers had observed the effects of glands like the thyroid and adrenals without having a unifying term for the chemical agents involved.
Hormone rapidly became one of the central organizing concepts in physiology. Within decades, researchers identified insulin, adrenaline, estrogen, testosterone, and dozens of other hormones, building an entire discipline of endocrinology around the word Starling introduced.
The Greek root reappeared in 1959 when scientists coined pheromone, combining pherein (to carry) with horman (to excite) to name chemical signals transmitted between organisms rather than within a single body. The two words are etymological cousins, both built from the Greek vocabulary of excitement and motion.