What is (a) Resembling the nipple or the breast; -- applied specifically to a process of the temporal bone behind the ear. (b) Pertaining to, or in the region of, the mastoid process; mastoidal called?

mastoid — (a) Resembling the nipple or the breast; -- applied specifically to a process of the temporal bone behind the ear. (b) Pertaining to, or in the region of, the mastoid process; mastoidal. (Webster's 1913.)

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