Effacement n. : The act if effacing; also, the result of the act.

Example:
Strep B test, and when do they start checking for dilation and Effacement?

Taxonomy
Effacement, cervix, free encyclopedia, mucus plug, search, been suggested that this article, Unsourced, shortening, tissue, early labour, bottleneck, centimeters, passes, passage, uterus, uterine wall, percentages, from zero.

Defination from the web:
effacement, the cervix is like a long bottleneck, usually about four centimeters in length. ... As effacement takes place, the cervix then shortens, or effaces, pulling up into the uterus and becoming part of the lower uterine wall. ...