| Noun | 1. | progesterone - a steroid hormone (trade name Lipo-Lutin) produced in the ovary; prepares and maintains the uterus for pregnancy anovulant, anovulatory drug, birth control pill, contraceptive pill, oral contraceptive, oral contraceptive pill, pill - a contraceptive in the form of a pill containing estrogen and progestin to inhibit ovulation and so prevent conception progestin, progestogen - any of a group of steroid hormones that have the effect of progesterone |