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1. Of, relating to, or resembling rock, especially in hardness; stony.
2. Of or relating to the very dense, hard portion of the temporal bone that forms a protective case for the inner ear.

[Middle English, from Old French petros, from Latin petrōsus, rocky, from petra, rock, from Greek petrā; see per- in Indo-European roots.]


(ˈpɛtrəs; ˈpiː-)
1. (Anatomy) anatomy denoting the dense part of the temporal bone that surrounds the inner ear
2. rare like rock or stone
[C16: from Latin petrōsus full of rocks]


(ˈpɛ trəs, ˈpi-)

like stone, esp. in hardness; stony; rocky.
[1350–1400; Middle English (< Middle French petros) < Latin petrōsus rocky.]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.petrous - (of bone especially the temporal bone) resembling stone in hardness
hard - resisting weight or pressure
References in periodicals archive ?
The favourite bone to get DNA from is the petrous bone - the inner-ear bone that extends inside the skull.
EAR WE GO: The favourite bone to get DNA from is the petrous bone - the inner-ear bone that extends inside the skull.
This case is an example of type D, in which the cervical, petrous, and cavernous segments of the ICA are absent, with the supraclinoid segment arising from an intracavernous vessel from the contralateral ICA.
Magnetic Resonance Imaging revealed hyperintensity in T1 axial flair and T2 weighted images in both mastoid air cells and petrous apex involving Dorello's canal and Meckel's cave area on right side.
Some secondary reasons have been reported: herpes zoster, temporomandibular joint dysfunction, nasopharyngeal carcinoma, petrous bone osteoma, and neuroborreliosis (5,6).
ET obliteration was systematically executed when the petrous apex pneumatization level was at least 2 of 4.
It was the petrous bone that gave such magnificent results," Zalloua said.
The boy was found to have a bleeding congenital aneurysm of the Petrous part of the internal carotid artery.
Expanded endonasal approach: vidian canal as a landmark to the petrous internal carotid artery.
In more severe cases, hyperpneumatization of equilateral mastoid cells and elevation of a petrous ridge and orbital roof can be seen [3].
Ancient-DNA expert Hannes Schroeder from the Natural History Museum of Denmark in Copenhagen will analyze the bones, including large pieces of skull, dental remains and both petrous bones 6 dense bones located behind the ears 6 which are particularly crucial because the petrous bones preserve DNA more efficiently than any other part of the skeleton or teeth.
This is a solid, and in some locations petrous, consistency with abundant collateral circulation.