Sentence:  He will immediately break in on their moſt <WSD>rooted</WSD> prejudices ; and with a kind of "malignant ſatisfaction" hack their darling notions with unſparing rigour and unbluſhing inſolence. 
Meaning of the word marked with <WSD> tags:  Ingrained, as through repeated use; entrenched; habitual or instinctive.