To become inflexible or unchangeable; to harden. Over time, his opinions began to calcify, making it difficult for him to accept new ideas.
To deposit calcium salts in soft tissue, causing it to harden. The doctor explained that the tissue had started to calcify, which was causing the stiffness.
To cause (a tissue or substance) to harden by depositing calcium salts; to make hard and inflexible. Long-term inflammation can calcify the tendons, reducing their elasticity.