progesterone (n.) Look up progesterone at Dictionary.com
female steroid sex hormone which prepares the uterus for child-bearing, 1935, from German Progesteron, from progestin (from which substance it was obtained), which had been coined 1930 from pro (see pro-) + Latin gestare, literally "to carry about" (see gestation), on notion of "substance which favors gestation." Also see -one.