From The Collaborative International Dictionary of English v.0.48 :
deep-rooted \deep-rooted\ adj.
well-established; as, deep-rooted prejudice.
Syn: deep-seated, fundamental, ingrained.
[WordNet 1.5]
From WordNet (r) 3.0 (2006) :
deep-rooted
adj 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"
[syn: deep-rooted, deep-seated, implanted,
ingrained, planted]