mifepristone
Concise Oxford English Dictionary © 2008 Oxford University Press:
mifepristone /ˌmɪfɛˈprɪstəʊn/
▶noun Medicine a synthetic steroid that inhibits the action of progesterone, given orally in early pregnancy to induce abortion.
– origin 1980s: prob. from Du. mifepriston, from mife- (representing aminophenol) + -pr- (representing propyl) + -ist- (representing oestradiol) + -one.
'mifepristone' also found in these Oxford entries:

