inveterate (adj.)
long-standing, deep-rooted
KJ V.ii.14 [Salisbury to Lewis the Dauphin] I am not glad that such a sore of time / Should ... heal the inveterate canker of one wound / By making many
R2 I.i.14 [John of Gaunt to King Richard] no inveterate malice
Tem I.ii.122 [Prospero to Miranda] This King of Naples, being an enemy / To me inveterate