1) Surgical instrument 
A cranioclast (from Greek κρανίον kranion `head, scull` and -κλάστης -klastes `breaker`) is surgical instrument akin to a strong forceps. It was once used to crush and then extract the skull of a fetus so as to facilitate delivery in cases of obstructed labour. == Pictures == Image:Medical_Instruments_O&G_Cranioclast_open.jpg|Ope...
• (n.) An instrument for crushing the head of a fetus, to facilitate delivery in difficult eases.
Instrument like a strong forceps formerly used for crushing and extracting the foetal head after perforation. ... Origin: cranio-+ G. Klao, to break in pieces ... (05 Mar 2000) ... 
Cra'ni·o·clast noun (Medicine) An instrument for crushing the head of a fetus, to facilitate delivery in difficult eases. 
Type: Term Pronunciation: krā′nē-ō-klast Definitions: 1. Instrument like a strong forceps formerly used for crushing and extracting the fetal head after perforation.