medical Definition of nuchal line
: any of several ridges on the outside of the skull: as
a
: one on each side that extends laterally in a curve from the external occipital protuberance to the mastoid process of the temporal bone — called also
superior nuchal line
b
: occipital crest a
c
: one on each side that extends laterally from the middle of the external occipital crest below and roughly parallel to the superior nuchal line — called also
inferior nuchal line
