Answer: ossified

AnswerCrossword Clue
OSSIFIEDFixed rigidly in a custom.
OSSIFIEDHardened
OSSIFIEDUltraconservative
OSSIFIEDHardened into bone
OSSIFIEDChanged into bone
ossifiedOSSIFY, to convert into bone
ossifiedto convert into bone