To make something hard or harder (tough, resistant to pressure).
To become or make (a person or thing) resistant or less sensitive.
To become or make (a consonant) more fortis; to (cause to) undergo fortition.
To strengthen.
To modify (a website or other system) to make it resistant to malicious attacks.
To unpalatalize or velarize.
To become hard (tough, resistant to pressure).
To be converted into glass, especially through heat.
To convert into glass or a glass-like substance by heat and fusion.