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 make something hard or harder (tough, resistant to pressure).
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 render capable of being acted on by actinic rays of light.
To make (someone) increasingly aware of, in a concerned or sensitive way.
To make (someone or something) sensitive or responsive to certain stimuli.