Synonyms of die-hard

1 Syllable
right, firm, mule
2 Syllables
hard-core, deep-down, deep-dyed, old-line, true-blue, tory, fogyish, standpat, rightist
3 Syllables
uncompliant, convinced, orthodox, undaring, extremist, doctrinal
4 Syllables
immovable, dyed-in-the-wool, intransigent, unwaivering, reactionaries, philistine, obscurantist, regressive, buttoned-down, reactionary, inflexible, unbendable
5 Syllables
well-established, unreconstructed, conservative, revolutionist, traditionalist
6 Syllables
traditionalistic
7 Syllables
ultraconservative
8 Syllables
counterrevolutionary