こわばる の訳語→ harden inert obdurate stiff stiffness stricken tense tighten
確固たる の訳語→ rigorous solid steadfast unshakable
固い の訳語→ firm formidable sealed severe tough
固く の訳語→ absolutely earnest heavily tensely tightly
石 の訳語→ flint stone
端然と の訳語→ primly self-possessed
rigidly