from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of or relating to the petrous and mastoid parts of the temporal bone; periotic.
from the GNU version of the Collaborative International Dictionary of English
- adj. Of or pertaining to the petrous and mastoid parts of the temporal bone, periotic.
from The Century Dictionary and Cyclopedia
- Of or pertaining to the petrous and mastoid parts of the temporal bone: as, petromastoid cells; the petromastoid bone.
- n. The petromastoid bone.
Sorry, no etymologies found.
The petromastoid part is developed from four centers, which make their appearance in the cartilaginous ear capsule about the fifth or sixth month.
The tympanic ring unites with the squama shortly before birth; the petromastoid part and squama join during the first year, and the tympanohyal portion of the styloid process about the same time (Figs. 143, 144).