from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A birth-control method dependent on abstinence during the period of ovulation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A method of natural birth control that involves counting days of a woman's menstrual cycle in order to determine when sexual intercourse is most or least likely to result in pregnancy.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. natural family planning in which ovulation is assumed to occur 14 days before the onset of a period (the fertile period would be assumed to extend from day 10 through day 18 of her cycle)
Sorry, no etymologies found.