the GNU version of the Collaborative International Dictionary of English
n. The formation of ova or eggs in the ovary, and the discharge of the same. In the human female the discharge occurs about halfway between menstruation times.
The Century Dictionary and Cyclopedia
n. The formation or production of ova or ovules; also, a discharge of an ovum from the Ovary.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. the expulsion of an ovum from the ovary (usually midway in the menstrual cycle)
Word Usage
"The fact that it releases some progestin would make me suspect that ovulation is suppressed somewhat, but if you are still getting your period while on the Mirena, I would suggest that you are ovulating."