nuchal line

noun

: 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 sense 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