The Collaborative International Dictionary
Cephalometer
Cephalometer \Ceph`a*lom"e*ter\, n. [Cephalo- + -meter.] (Med.) An instrument measuring the dimensions of the head of a fetus during delivery.
Wiktionary
cephalometer
n. 1 An instrument for measuring the head. 2 A device for positioning the head, and holding it steady, for an X-ray or surgery; a cephalostat.