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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 ?
ten adults (according to the number of petrous parts of temporal bones),
An otherwise healthy 21-year-old woman presented to the outpatient clinic with advanced cholesteatoma of the skull base involving the petrous apex (figure 1).
The vestibular apparatus is located in the inner ear and forms the peripheral component of the vestibular system, which lies in the otic capsule in the petrous part of the temporal bone.
PETROUS A Coastal bird B Of less importance C Stony who am I?
Maria aged 12 (left) with mum and dad |Petrous and Yiola Petrou and sister Lisa at the family fish and chip shop.
Strikingly, in three cases, cut-marks were observed inside the cranium (twice upon the petrous region of the temporal bone, and once upon the sphenoid body) (Figure 11).
In the temporal lobe, injury occurs adjacent to the petrous bone and greater sphenoid wing (Figure 9).
Three additional cases of otitis media with petrous apex and cranial base involvement were subsequently reported by Farr et al (6) in 1992, Weingarten et al (7) in 1993, and Blackledge et al (8) in 2001.
In tuberculosis, the mastoid, middle ear, or petrous bone is often involved (1, 2).
Neurotologists, otolaryngologists, and skull base surgeons from the US outline a practical approach to the clinical management of skull base tumors and lesions, beginning with surgical approaches described from the neurotologist's and neurosurgeon's perspectives, then minimally invasive and endoscopic skull base approaches; specific tumors and approaches, including acoustic neuroma, meningioma, neurofibromatosis, petrous apex lesions, and petroclival tumors; temporal bone malignancies; unusual temporal bone lesions, such as Paget's disease, fibrous dysplasia, and osteopetrosis; stereotactic radiotherapy for various types of skull base pathology; and the importance, benefit, and interpretation of intraoperative monitoring.
pierces the dura below the posterior clinoids and angles forward over the tip of the petrous bone, passing through or around the inferior petrosal sinus, through the Dorello canal (under the petroclinoid ligament) to enter the cavernous sinus (Fig.
Transverse temporal bone fractures extend across the petrous ridge, with the fracture beginning in the posterior fossa and crossing the otic capsule into the middle ear space.