deep-rooted

Meaning

1. adjective Of a plant, having deep roots.
2. adjective Of a non-living object, deeply and firmly embedded (in the ground, etc.)
3. adjective Firmly established in thought or behavior and difficult to change.

   They avoid conflict at all costs because of their deep-rooted fear of upsetting people.

Similar words

established deep-seated ingrained implanted planted long-established well-established long-standing thoroughgoing in-depth