Daily Chinese Idiom Guessing Game
Deeply rooted and firmly established, often used to describe habits, ideas, or problems that are difficult to change.
比喻基础深厚，不容易动摇。
《老子》有国之母，可以长久，是谓深根固柢，长生久视之道。”《韩非子·解老》柢固则生长，根深则视久。”
His prejudice against new technology is deeply entrenched.