[pe.trous] adj [ME, fr. MF petreux, fr. L petrosus, fr. petra rock, fr. Gk] (14c): of, relating to, or constituting the exceptionally hard and dense portion of the human temporal bone that contains the internal auditory organs
PETROUS
Meaning of PETROUS in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012