Definition of effacing:
(v) :
(transitive) To erase (as anything impressed or inscribed upon a surface); to render illegible or indiscernible.
(v) :
(transitive) To cause to disappear as if by rubbing out or striking out.
(v) :
(intransitive) To make oneself inobtrusive as if due to modesty or diffidence.
(v) :
(medicine, intransitive) Of the cervix during pregnancy, to thin and stretch in preparation for labor.
(v) :
(medicine, intransitive) Of a woman: to have the cervix thin and stretch in this manner.