deep seated

deeply rooted, deep rooted, firmly fixed (used particularly of ideas or principles)

Adjective
1. (used especially of ideas or principles) deeply rooted; firmly fixed or held; "deep-rooted prejudice"; "deep-seated differences of opinion"; "implanted convictions"; "ingrained habits of a lifetime"; "a deeply planted need"
(synonym) deep-rooted, implanted, ingrained, planted
(similar) established, constituted