ingrained
/ɪnˈgreɪnd; ɪn`ɡrend/ adj
1 (of habits, tendencies, etc) deeply fixed; thorough （指习惯、 习性等）根深蒂固的, 一成不变的
ingrained prejudices, suspicions, assumptions, etc 由来已久的成见、 怀疑、 臆见等.
2 (of dirt, stains, etc) going deeply into a substance, and therefore difficult to clean off （指尘土、 污迹等）积深而难於清除的
deeply ingrained dirt 积聚得很深的污垢.