noun

1. a substance formed in some organ of the body, as the adrenal glands, the pituitary, etc., and carried by a body fluid to another organ or tissue, where it has a specific effect: now often prepared synthetically
2. a similar substance produced in a plant, as an auxin

Etymology: < Gr hormōn, prp. of horman, to stimulate, excite < hormē, impulse < IE base *ser-, to stream > Sans sará-, fluid, L serum, whey