/proh jes"teuh rohn'/ , n.
1. Biochem. a hormone, C 21 H 30 O 2 , that prepares the uterus for the fertilized ovum and maintains pregnancy.
2. Pharm. a commercial form of this compound, obtained from the corpus luteum of pregnant sows or synthesized: used in the treatment of dysfunctional uterine bleeding, dysmenorrhea, threatened or recurrent abortion, etc.
[ 1930-35; b. PROGESTIN and luteosterone ( Luteosteron, synonymous with progestin, equiv. to Luteo- LUTEO- (repr. CORPUS LUTEUM) + -steron (see STEROL, -ONE)) ]