Hardened in feelings, esp. against moral or mollifying influences; unyielding; hard-hearted; stubbornly wicked.
- Hardened in wrongdoing or wickedness; stubbornly impenitent: "obdurate conscience of the old sinner” ( Sir Walter Scott).
- Hardened against feeling; hardhearted: an obdurate miser.
- Not giving in to persuasion; intractable. See Synonyms at inflexible.