occipital protuberance
nounMedical Definition of occipital protuberance
: either of two prominences on the occipital bone:
a
: a prominence on the outer surface of the occipital bone midway between the upper border and the foramen magnum that with the external occipital crest gives attachment to the ligamentum nuchae
— called also external occipital protuberance, inion
b
: a prominence similarly situated on the inner surface of the occipital bone
— called also internal occipital protuberance