the killing of one's child.
Origin of prolicide
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
It is hoped that this word will be considered entitled to reception, on the score of analogy. We have long had parricide, fratricide, and infanticide, all (if I may use the figure of speech,) of the same family; and recently the very appropriate term foeticide has been introduced into Forensic Medicine. In both these last crimes there is a peculiarity arising from the person accused being, in almost every instance, the parent .... In this relation to the beings destroyed, the general term of murderer, or murder of offspring seems to be the fair converse of parricide; and will suit well the purpose of the Medico-legal writer, who considers the two cases as parts of one subject, for the designation of which collectively a proper term was wanting. [Smith]
Online Etymology Dictionary, © 2010 Douglas Harper