Synonyms of deep-down

1 Syllable
true
2 Syllables
die-hard, deep-dyed, thorough, utter, fixed
3 Syllables
hardened, deep-rooted, deep-seated, complete, entrenched, full-fledged, infixed, ingrained, instilled, thoroughgoing, long-standing, genuine, confirmed
4 Syllables
dyed-in-the-wool, absolute, unchangeable, congenital
5 Syllables
uncompromising, well-established