刻骨 | kè gǔ | ingrained / entrenched / deep-rooted | |
积重难返 | jī zhòng nán fǎn | ingrained habits are hard to overcome (idiom) / bad old practices die hard | |
苦大仇深 | kǔ dà chóu shēn | great bitterness, deep hatred (idiom) / deeply ingrained long-standing resentment | |
习以成性 | xí yǐ chéng xìng | deeply ingrained / steeped in |